Blood test markers
Blood test markers
Every marker in plain words: what it measures, what reference ranges the guidelines give, when it is ordered and what a result outside the range usually means.
- All markers
- 186All markers
- By category
- 19By category
Full blood count20
- Basophils Blood Test: Normal Range & ResultsWhat basophils show in a blood test, the MedlinePlus range of 0.5–1 % of all white blood cells in adults, and what a raised or reduced result can mean.
- Blood Group Test (Blood Type): ABO and Rh FactorWhat a blood group test shows about the ABO group and the Rh factor, why it matters before a transfusion and during pregnancy, and how common each group is.
- Complete Blood Count (CBC): Normal RangesWhat a complete blood count measures, the normal ranges for haemoglobin, white cells and platelets, and what a raised or low result can mean.
- Eosinophils Blood Test: Normal Range & ResultsWhat eosinophils show in a blood test, the MedlinePlus range of less than 500 cells per microlitre, and what a raised or reduced result can mean.
- G6PD Test: What It Shows and What Low Activity MeansWhat the G6PD blood test shows, why there is no single normal value, and what reduced enzyme activity means, according to MedlinePlus.
- Haematocrit Test: Normal Range & What Results MeanWhat haematocrit shows in a blood test, the MedlinePlus normal ranges for men and women, and what a low or a raised result can mean.
- Haemoglobin Levels: Normal Range for Women and MenWhat haemoglobin measures, the WHO 2024 anaemia thresholds by age, sex and pregnancy, and what a low or high result can mean.
- Lymphocytes Blood Test: Normal Range & ResultsWhat lymphocytes show in a blood test, the MedlinePlus range of 20–40% of all white cells, and what a raised or low result can mean.
- MCHC Blood Test: Normal Range & What It MeansWhat MCHC (mean corpuscular haemoglobin concentration) shows in a blood test, the MedlinePlus range of 320-360 g/l for adults, and what low or high means.
- MCV Blood Test: Normal Range & What It MeansWhat MCV (mean corpuscular volume) shows in a blood test, the MedlinePlus normal range of 80-100 fl for adults, and what a low or high result can mean.
- Monocytes Blood Test: Normal Range & ResultsWhat monocytes show in a blood test, the MedlinePlus range of 2–8 % of white blood cells in adults, and what a raised result can mean.
- MPV Blood Test: What a High or Low MPV MeansWhat MPV (mean platelet volume) shows in a full blood count, why it is read together with the platelet count, and what a high or low MPV can mean.
- Neutrophils Blood Test: Normal Range & ResultsWhat neutrophils show in a blood test, the MedlinePlus range of 40–60% of all white cells in adults, and what a raised or low result can mean.
- PDW Blood Test: What It Means and ResultsWhat PDW (platelet distribution width) shows in a full blood count, why it is read together with PLT and MPV, and what a raised or low result can mean.
- Platelet Count: Normal Range & ResultsWhat a platelet count shows, the MedlinePlus range of 150–400 ×10⁹/l for adults, and what a low or raised result can mean.
- RDW Blood Test: What a High RDW MeansWhat RDW (red cell distribution width) shows in a full blood count, why it is read together with MCV, and what a raised RDW can mean.
- Red Blood Cell Count: Normal Range & ResultsWhat a red blood cell count (RBC) measures, the MedlinePlus reference ranges for men and women, and what a raised or low result can mean.
- Reticulocyte Count: Normal Range & ResultsWhat a reticulocyte count shows, the MedlinePlus reference range for healthy adults, and what a raised or low result can mean.
- What Is MCH in a Blood Test? Normal Range, Low and HighWhat MCH (mean corpuscular haemoglobin) shows in a blood test, the MedlinePlus range of 27-32 pg for adults, and what a low or high result can mean.
- White Blood Cell Count: Normal Range & ResultsWhat a white blood cell count measures, the MedlinePlus range of 4.5–11.0×10⁹/l for adults, and what a raised or low result can mean.
Lipids and cholesterol11
- ApoB/ApoA1 Ratio: What the Blood Test ShowsWhat the ApoB/ApoA1 ratio compares, when it is tested and what a higher or lower result can mean — MedlinePlus gives no universal numeric limit for it.
- Apolipoprotein A1 (ApoA1) Test: Normal RangeWhat the apolipoprotein A1 (ApoA1) test measures, the reference range in mg/dL, and what a low or high result can mean.
- Apolipoprotein B (ApoB) Test: What It ShowsWhat the apolipoprotein B (ApoB) test shows, how it differs from LDL cholesterol and what a raised or low result can mean. Your lab gives the exact interval.
- Apolipoprotein E (ApoE) Test: e2, e3 and e4What the apolipoprotein E (ApoE) test shows, why it is most often done as APOE genotyping (e2, e3, e4), and what each result can mean.
- Cholesterol Test: Normal Range and ResultsWhat a total cholesterol test measures, the NHS reference ranges in mmol/l, whether you need to fast, and what a high or low result can mean.
- HDL Cholesterol Test: Normal Range and ResultsWhat HDL ("good") cholesterol measures, the NHS and MedlinePlus reference values in mmol/l, and what a low or a high result can mean.
- LDL Cholesterol Test: Normal Range and ResultsWhat LDL ("bad") cholesterol measures, the desirable value in mmol/l, what a raised result can mean, and why the target depends on overall heart risk.
- Lipid Panel (Lipid Profile): Normal Ranges ExplainedWhat a lipid panel measures — total cholesterol, LDL, HDL and triglycerides — the adult reference ranges, and what a raised or low result can mean.
- Lipoprotein(a) Test: What Lp(a) ShowsWhat the lipoprotein(a) blood test shows, why the Lp(a) level is mostly set by the genes and what a high result can mean. Your own lab gives the interval.
- Non-HDL Cholesterol: Normal Range and Test ResultsWhat non-HDL cholesterol is, how it is calculated from a lipid panel, the MedlinePlus healthy values for adults and children, and what a raised result can mean.
- Triglycerides Test: Normal Range and ResultsWhat a triglycerides blood test measures, the normal, borderline, high and very high ranges in mmol/l, and why you fast 8-12 hours beforehand.
Glucose and diabetes6
- Blood Glucose Test: Normal Range ExplainedWhat a fasting blood glucose test measures, the normal, prediabetes and diabetes ranges by ADA criteria, and how to prepare for the test.
- C-Peptide Test: Normal Range and ResultsWhat a C-peptide test measures, the normal range in adults, what a low or high result can mean, and how to prepare for the test.
- Glucose Tolerance Test: Normal Range ExplainedWhat the glucose tolerance test (OGTT) measures, the normal, impaired and diabetes ranges 2 hours after a 75 g glucose load, and how to prepare.
- HbA1c Test: Normal Range and ResultsWhat HbA1c (glycated haemoglobin) shows about average glucose over 2–3 months, the ADA normal, prediabetes and diabetes ranges, and when it can be inaccurate.
- HOMA-IR Index Explained: Insulin Resistance TestWhat the HOMA-IR index is, how it is calculated from fasting glucose and insulin, and what a raised result can mean. Reference limits depend on the laboratory.
- Insulin Test Explained: High and Low ResultsWhat a blood insulin test measures, why it is taken after 8-12 hours of fasting, and what a high or low result can mean when read alongside glucose.
Liver markers15
- Albumin Blood Test: Normal Range and ResultsThe MedlinePlus range for albumin in adults is 34-54 g/l (3.4-5.4 g/dl). What low and raised albumin can mean, and why albumin matters for calcium.
- Alkaline Phosphatase (ALP) Test: Normal RangeWhat the alkaline phosphatase (ALP) blood test shows, the MedlinePlus adult range of 40–129 U/l, and what a raised or a low result can mean.
- ALT Blood Test: Normal Range and What It MeansWhat the ALT blood test shows, the MedlinePlus adult range of 4–36 U/l, what a raised or a low result can mean.
- Amylase Test: Normal Range and What It MeansWhat the amylase blood test shows, the MedlinePlus adult range of 40–140 U/l, and why the level rises in pancreatitis.
- AST Blood Test: Normal Range and What It MeansWhat the AST blood test shows, the MedlinePlus adult range of 8–33 U/l, what a raised or a low result can mean.
- Bile Acids Test Explained: Results and PregnancyWhat the bile acids blood test shows, when it is done, and what a raised result can mean — including itching in pregnancy (ICP).
- Bilirubin Test: Normal Range and High BilirubinWhat a bilirubin test shows, the normal range in adults of 1.71–20.5 µmol/l per MedlinePlus, and what a raised direct or indirect result can mean.
- Ceruloplasmin Test: Normal Range & ResultsWhat a ceruloplasmin test shows, the range in adults of 20–40 mg/dl (0.2–0.4 g/l), and what a low or raised result can mean.
- Direct Bilirubin Test: Normal Range and ResultsWhat the direct (conjugated) bilirubin test shows, the adult normal value below 5.1 µmol/l per MedlinePlus, and what a raised result can mean.
- GGT Test Explained: Normal Range and ResultsWhat the GGT blood test shows, the MedlinePlus adult range of 5–40 U/l, what a raised or a low result can mean.
- LDH Blood Test: Normal Range and What It MeansWhat the LDH blood test shows, the MedlinePlus adult range of 125–220 U/l, and what a raised or a low result can mean.
- Lipase Test: Normal Range and What It MeansWhat the lipase blood test shows, the MedlinePlus adult range of 0–160 U/l, why the level rises in acute pancreatitis and what a low result can mean.
- Pancreatic Amylase Test ExplainedWhat a pancreatic amylase (P-AMYL) test measures, the adult reference range in Lithuanian labs, and what a high or low result can mean.
- Total Protein Test: Adult Range 65-81 g/lWhat the total protein blood test measures, the adult reference range of 65-81 g/l according to MedlinePlus, and what a high or low result can mean.
- Valproic Acid Test: Therapeutic Range ExplainedWhat the valproic acid blood test measures, the MedlinePlus therapeutic range for adults of 50–100 mcg/ml, and what a high or a low result can mean.
Kidney markers7
- Albumin-Creatinine Ratio (ACR): Normal RangeWhat the urine albumin-creatinine ratio (ACR) shows, the MedlinePlus normal value of under 30 mg/g creatinine, and what a higher result can mean.
- Creatinine Blood Test ExplainedWhat creatinine measures, MedlinePlus reference ranges for men and women, and what raises or lowers it.
- Creatinine Clearance Test: Normal RangeWhat the creatinine clearance test measures, the MedlinePlus normal ranges for men and women, and what a low or a high result can mean.
- Cystatin C Test Explained: Kidney FunctionWhat the cystatin C blood test measures, when a doctor may order it instead of creatinine, and what a raised result can mean for kidney function.
- GFR Test Explained: eGFR Normal RangeWhat the eGFR (GFR) test measures, the NHS stages G1 to G5, and why a value below 60 ml/min/1.73 m² counts only when it persists.
- Urea Test (BUN): Normal Range & ResultsWhat the urea (BUN) blood test shows, the adult reference range per MedlinePlus, and what a high or a low result can mean.
- Uric Acid Test: Normal Range and ResultsWhat a uric acid blood test shows, the normal range for women and men in µmol/l and mg/dl, and what a raised or low result can mean.
Electrolytes and minerals14
- Bicarbonate (CO2) Blood Test: Normal RangeWhat the bicarbonate (total CO2) blood test measures, the normal range for adults of 23–29 mmol/l, and what a high or low result can mean.
- Calcium Blood Test: Normal Range and ResultsThe MedlinePlus range for total calcium in adults is 2.20-2.58 mmol/l (8.8-10.3 mg/dl). What high and low calcium can mean, and why albumin matters.
- Chloride Blood Test: Normal RangeWhat the chloride blood test measures, the normal value for adults of 98–107 mmol/l, and what a raised or low result can mean.
- Copper Blood Test: What the Result MeansWhat a copper blood test shows, why it is read with ceruloplasmin, and what high or low copper can mean — including Wilson's disease.
- Corrected Calcium Test: Normal Range and ResultsCorrected calcium is total calcium recalculated for albumin. Per MedlinePlus, the range in adults is 2.20-2.58 mmol/l (8.8-10.3 mg/dl).
- Iodine Test: Levels, Deficiency and ExcessWhat an iodine test shows, the 150 µg of iodine a day MedlinePlus recommends for adults, and what a low or raised result can mean.
- Ionised Calcium Blood Test ExplainedWhat an ionised calcium (free calcium) test measures, why the laboratory sets its own reference interval, and what a high or low result can mean.
- Lithium Blood Test Explained: Levels & MonitoringWhy the lithium level is monitored during treatment, when blood is taken, how often the NHS says it is tested, and what a high or low result can mean.
- Magnesium Test: Normal Range & What Results MeanWhat a magnesium blood test shows, the adult range of 0.70–0.91 mmol/l per MedlinePlus, and why a normal result does not rule out a deficiency.
- Phosphorus Blood Test ExplainedWhat a phosphorus blood test shows, the MedlinePlus ranges for adults and children, and what a high or low result can mean.
- Potassium Test: Normal Range & What Results MeanWhat a potassium blood test shows, the adult range of 3.7–5.2 mmol/l per MedlinePlus, and what a high or low result can mean.
- Selenium Test: What the Blood Result MeansWhat a selenium test shows, when it is ordered, the daily amount of selenium given by MedlinePlus, and what a low or raised result can mean.
- Sodium Blood Test: Normal Range & ResultsThe adult sodium range is 135–145 mmol/l per MedlinePlus. What raised and low sodium can mean, and why it usually reflects water balance, not salt.
- Zinc Test: What the Blood Result MeansWhat a zinc blood test shows, when it is ordered, and what a low or raised result can mean, with the daily amount of zinc given by MedlinePlus.
Vitamins16
- Active B12 Test (HoloTC) ExplainedWhat the active B12 (holotranscobalamin) test measures, why laboratories set their own thresholds for it, and what a low or high result can mean.
- Biotin (Vitamin B7) Test: Results ExplainedWhat the biotin (vitamin B7) blood test is for, why there is no widely used standard reference range, and what a low or a high result can mean.
- Calcitriol Test: 1,25-Dihydroxyvitamin D ExplainedWhat the 1,25-dihydroxyvitamin D (calcitriol) test measures, when a doctor orders it, and why it does not replace the usual 25-OH vitamin D test.
- Folic Acid Test: Normal Range and ResultsWhat the folic acid (folate) test measures, the MedlinePlus adult range of 6.12–38.52 nmol/l, what a low result can mean, and how to prepare.
- Omega-3 Index Test: What Your Result ShowsThe omega-3 index shows what share of red blood cell membrane fatty acids is EPA and DHA: what it measures, when it is tested, how to read it.
- Red Blood Cell Folate Test: Normal Range and ResultWhat red blood cell folate shows, WHO's 226.5 nmol/l deficiency threshold, the 906 nmol/l population target for women of reproductive age, and how to prepare.
- Vitamin A Test: Normal Range and ResultsWhat the vitamin A (retinol) blood test measures, the range for adults of 1.1–4.2 µmol/l per MedlinePlus, and what a low or high result can mean.
- Vitamin B1 (Thiamine) Test: What the Result MeansWhat the vitamin B1 (thiamine) blood test shows, when it is ordered, how to prepare, and what a low or high result can mean per MedlinePlus.
- Vitamin B12 Test: Normal Range and ResultsWhat the vitamin B12 test measures, the MedlinePlus normal range of 219–773 pmol/l, what a low or high result can mean, and how to prepare.
- Vitamin B2 (Riboflavin) Test: Results ExplainedWhat the vitamin B2 (riboflavin) blood test is for, why no single universal reference range is published, and what a low or high result can mean.
- Vitamin B3 (Niacin) Test: What It ShowsWhat the vitamin B3 (niacin) blood test is for, why it is done rarely, and what a deficiency (pellagra) or an excess can mean per MedlinePlus.
- Vitamin B6 Test: What the Result MeansWhat the vitamin B6 (pyridoxal phosphate) blood test shows, when it is ordered, the signs of deficiency and what long-term high-dose supplements can cause.
- Vitamin C Test: What the Blood Result MeansWhat the vitamin C (ascorbic acid) blood test shows, when it is done, and what a low or high result can mean. Per the NHS, a lasting shortage can cause scurvy.
- Vitamin D Blood Test ExplainedWhat the 25(OH)D vitamin D test measures, the recommended blood level per MedlinePlus, and causes of high and low results.
- Vitamin E Test: Normal Range Depends on AgeWhat the vitamin E (tocopherol) blood test measures, why the normal range depends on age, and what a low or a high result can mean.
- Vitamin K Test: What It Shows and Daily NeedsWhat vitamin K does, how much adults need each day per the NHS, why a shortage raises the bleeding tendency, and why newborns usually get a dose.
Iron and anaemia6
- Ferritin Blood Test ExplainedWhat a ferritin test measures, WHO 2020 reference ranges by group, and what causes high or low results.
- Iron Blood Test: Normal Range and ResultsWhat a serum iron test measures, the MedlinePlus ranges for men and women, and why iron is read together with ferritin, transferrin saturation and TIBC.
- Soluble Transferrin Receptor (sTfR) Test ExplainedWhat the soluble transferrin receptor (sTfR) test shows, when a doctor orders it, and why the reference limit depends on the laboratory method.
- TIBC Test: Normal Range and ResultsWhat the TIBC blood test measures, the MedlinePlus reference ranges for men and women, and what a raised or a low result can be linked to.
- Transferrin Saturation: Normal Range & ResultsWhat transferrin saturation shows, the MedlinePlus ranges for men (20–50%) and women (15–45%), and what a high or low result can mean.
- Transferrin Test: Normal Range and ResultsWhat the transferrin blood test measures, the adult reference range of 215–380 mg/dl, and what a raised or a lowered result can mean.
Thyroid11
- Calcitonin Test Explained: Normal RangeWhat a calcitonin blood test shows, the normal values MedlinePlus gives for men and women, and what a raised or low result can mean.
- Free T3 (FT3) Test: Normal Range and ResultsWhat a free T3 (FT3) test measures, the range for adults of 3.2-6.8 pmol/l, and what a high or low result can mean.
- Free T4 Test Explained: Normal Range & ResultsWhat the free T4 (FT4) test measures, the usual adult range of 10.3–24.5 pmol/l, and what a raised or low result can mean.
- Reverse T3 (rT3) Test ExplainedWhat reverse T3 (rT3) is, why the American Thyroid Association does not consider the test clinically useful in healthy people, and what is used instead.
- T3 Test Explained: Normal Range & ResultsWhat a T3 (triiodothyronine) blood test measures, the normal range MedlinePlus gives for adults, and what a raised or low result can mean.
- T4 Test Explained: Total Thyroxine ResultsWhat a T4 (thyroxine) blood test measures, why total T4 is assessed together with TSH and free T4, and what a raised or low result can mean.
- Thyroglobulin Antibodies (Anti-TG) Test ExplainedWhat the thyroglobulin antibody (anti-TG) test shows, what a negative and a positive result mean, and which thyroid measures it is assessed with.
- Thyroglobulin Test Explained: What Results MeanWhat a thyroglobulin (Tg) blood test shows, why it is used mainly after thyroid cancer treatment, and why the reference interval depends on the laboratory.
- TPO Antibodies (Anti-TPO) Test ExplainedWhat the anti-TPO (TPO antibodies) test shows, what a raised result means, and why the numeric range depends on the laboratory method.
- TSH Receptor Antibodies (TRAb) Test: Normal RangeWhat the TSH receptor antibody test (TRAb, also called TSI) shows, what counts as a normal result, and what raised antibodies can mean.
- TSH Test Explained: Normal Range & ResultsWhat TSH (thyrotropin) measures, the typical adult reference range, and what a high or low result can mean.
Sex hormones13
- AMH Test: What It Shows About Ovarian ReserveWhat an AMH (anti-Müllerian hormone) test shows about the ovarian reserve, why there is no standardised range, and what a raised or a low result can mean.
- Beta hCG Test: Normal Range and ResultsWhat the quantitative beta hCG blood test shows, the MedlinePlus normal values for non-pregnant women, men and pregnancy, and what a high or low result means.
- DHEA-S Test: Normal Range by Age and SexWhat the DHEA-S (DHEA sulfate) test measures, the adult reference ranges by age and sex, and what a raised or a low result can mean.
- Estradiol Test: Normal Range for Women and MenWhat an estradiol (E2) test measures, the MedlinePlus ranges for men and for women before and after menopause, and what a high or low result can mean.
- Estriol Test in Pregnancy: Free Estriol (uE3)What the free estriol (uE3) test shows, why it is assessed together with AFP, hCG and inhibin A in the quad screen, and what a low result can mean.
- Free Androgen Index (FAI): What the Test ShowsWhat the free androgen index (FAI) is, how it is calculated from total testosterone and SHBG, and what a raised or a low result can mean.
- FSH Test: Normal Range for Women and MenWhat an FSH test shows, the MedlinePlus ranges for women, men and children, and what a raised or a low result can mean.
- hCG Test: Normal Levels by Week & ResultsWhat the hCG blood test shows, the MedlinePlus levels for non-pregnant women, men and by week of pregnancy, and what a high or low result can mean.
- LH Test: Normal Range for Women and MenWhat an LH (luteinizing hormone) test measures, the MedlinePlus ranges before and after menopause and for men, and what a raised or low result can mean.
- Progesterone Test: Normal Range by Cycle PhaseWhat a progesterone test shows, the MedlinePlus ranges before and after ovulation and in each trimester, and what a raised or low result can mean.
- Prolactin Test Explained: Normal RangeWhat a prolactin test measures, the MedlinePlus ranges for men, non-pregnant and pregnant women, and what a raised or low result can mean.
- SHBG Test: What It Shows and What Affects ItWhat the SHBG (sex hormone binding globulin) test shows, why it is done together with total testosterone, and what a raised or a low result can mean.
- Testosterone Test: Normal Range by Age and SexWhat a testosterone test measures, the normal ranges for men and women by age, why blood is taken in the morning, and what a high or low result can mean.
Other hormones7
- ACTH Test Explained: Normal Range & ResultsWhat the ACTH blood test measures, the 2-12 pmol/l morning range for adults given by MedlinePlus, and what a raised or low result can mean.
- Catecholamines Test: Normal Range in UrineWhat the 24-hour urine catecholamines test measures, the adult ranges for dopamine, adrenaline and noradrenaline, and what a raised result can mean.
- Cortisol Test Explained: Normal Range & ResultsWhat the cortisol blood test measures, the 138-690 nmol/l morning range for adults given by MedlinePlus, and what a high or low result can mean.
- Growth Hormone Test: Normal Range and ResultsWhat the growth hormone (GH) test measures, the adult ranges MedlinePlus gives for men and women, and what a raised or low result can mean.
- IGF-1 Test: What It Measures and ResultsWhat the IGF-1 test measures, when it is ordered and what a raised or low result can mean — an indirect indicator of growth hormone status.
- Parathyroid Hormone (PTH) Test: Normal RangeWhat the parathyroid hormone (PTH) test shows, the adult reference range according to MedlinePlus, and what a raised or low result can mean.
- Salivary Cortisol Test Explained: What It ShowsWhat the salivary cortisol test shows, why the sample is often taken at several times of day, and what a raised or low result can mean.
Inflammation and immunity12
- ASO Titre Test Explained: Antistreptolysin OWhat the ASO (antistreptolysin O) titre test shows, when a doctor orders it, and what a raised, positive result can mean after a strep infection.
- Calprotectin Stool Test: What It ShowsWhat a calprotectin stool test measures, why it helps tell inflammatory bowel disease from IBS, and what a raised or normal result means per MedlinePlus.
- Complement C3 Blood Test: What Results MeanWhat the complement C3 blood test shows, why it is used in lupus and rheumatoid arthritis, and what a low or a raised result can mean.
- Complement C4 Test: What the Result MeansWhat the complement C4 blood test shows, why it is assessed together with C3 in lupus, and what a raised or lowered result may mean.
- CRP Blood Test ExplainedWhat CRP (C-reactive protein) measures, MedlinePlus reference ranges, what raises or lowers it, and hs-CRP for heart risk.
- ESR Test Explained: Normal Ranges by Age and SexWhat the ESR (erythrocyte sedimentation rate) test measures, MedlinePlus normal ranges by age and sex, and what a raised or a low result can mean.
- hs-CRP Test: Normal Range and Cardiovascular Risk LevelsWhat the high-sensitivity CRP test measures, the MedlinePlus reference value and the AHA risk bands: below 1 mg/l, 1–3 mg/l and above 3 mg/l.
- IgA Blood Test (Immunoglobulin A): What It ShowsWhat the IgA (immunoglobulin A) blood test shows, when a doctor orders it, and what a low or a raised result can mean, per MedlinePlus.
- IgG Blood Test (Immunoglobulin G): Normal RangeWhat the IgG (immunoglobulin G) blood test shows, the MedlinePlus adult range of 7.0–16.0 g/l, and what a high or low result can mean.
- IgM Blood Test (Immunoglobulin M): What It ShowsWhat the IgM (immunoglobulin M) blood test shows, why it is done together with IgG and IgA, and what a raised or low result can mean.
- Procalcitonin Test: What the Result MeansWhat the procalcitonin (PCT) test shows, why it helps tell a bacterial infection from a viral one, and what a high or falling result may mean.
- Protein Electrophoresis Test: Normal RangesWhat the protein electrophoresis (protein fractions) test shows, the adult reference ranges for albumin and the globulin fractions, and what a result means.
Heart markers6
- CK-MB Test Explained: What the Result ShowsWhat the CK-MB fraction of creatine kinase shows, when it is tested alongside troponin and total CK, and why the result is always assessed together with them.
- Creatine Kinase (CK) Test: Normal RangeWhat a creatine kinase (CK) test shows, the MedlinePlus adult range of 10-120 mcg/l, and why a raised CK is assessed together with symptoms and other tests.
- Homocysteine Test: What a High Result MeansWhat the homocysteine blood test shows, why a raised result may point to a vitamin B12 or folic acid deficiency, and how to prepare for it.
- Lp-PLA2 Test Explained: What It ShowsWhat the Lp-PLA2 blood test shows, why no commonly accepted normal range is given for it, and why it is read alongside cholesterol, LDL and CRP.
- NT-proBNP Test Explained: What the Result ShowsWhat an NT-proBNP test shows in breathlessness or swelling, the ESC 2026 and NICE decision thresholds, and why your lab's own range applies.
- Troponin Test: What It Means, Normal Range, High LevelsWhat a troponin test shows, why it is repeated after a few hours and what a raised result can mean. Reference limits depend on the laboratory and the method.
Blood clotting5
- APTT Test (PTT): What the Result MeansWhat the APTT (PTT) test measures, when it is done, why the reference range depends on the laboratory, and what a prolonged or shortened result can mean.
- D-Dimer Test Explained: What the Result MeansWhat a D-dimer test measures, what a negative (low) result usually means, and why a raised result usually means further tests are needed.
- Fibrinogen Test: Normal Range & ResultsWhat the fibrinogen test measures, the normal range in adults (2.0–4.0 g/l per MedlinePlus), and what a high or low result can mean.
- Protein C and Protein S Test: What It ShowsWhat the protein C and protein S tests measure, when a doctor orders them, how to prepare, and what a low or poorly working result can mean.
- Prothrombin Time Test (PT/INR): Normal RangeWhat the prothrombin time (PT) and INR measure, the normal range for adults not taking blood thinners, and what a high or low result can mean.
Tumour markers13
- AFP Test Explained: Alpha-Fetoprotein Tumour MarkerWhat the AFP (alpha-fetoprotein) tumour marker test measures, why it has no single numeric range, and what a raised or falling result can mean.
- CA 125 Test Explained: Normal Range and ResultsWhat the CA 125 blood test shows, why above 35 U/ml is treated as raised in adult women, and why a raised result alone does not mean cancer.
- CA 15-3 Test Explained: What the Result MeansWhat the CA 15-3 blood test shows, why it is used to follow treatment of advanced breast cancer, and why a raised result on its own is not a diagnosis.
- CA 19-9 Test Explained: What the Result MeansWhat the CA 19-9 blood test shows, why it is used to follow already diagnosed cancer, and why a raised result on its own is not a diagnosis.
- CA 72-4 Test Explained: What the Result MeansWhat the CA 72-4 blood test shows, why it is most often used after a cancer diagnosis, and why a raised result on its own does not confirm a diagnosis.
- CEA Test Explained: Normal Range & ResultsWhat the CEA blood test shows, what is considered normal for adults who do not smoke and who smoke, and why a raised result alone does not mean cancer.
- CYFRA 21-1 Test: What the Result MeansWhat the CYFRA 21-1 blood test shows, why it is most often done when a cancer diagnosis is already known, and why one result on its own is not a diagnosis.
- Fecal Occult Blood Test (FOBT/FIT) ExplainedWhat a fecal occult blood test (FOBT, iFOBT/FIT) detects, why it is used to screen for colon cancer, and what a positive result means per MedlinePlus.
- Free PSA Test (fPSA): What Your Result MeansWhat free PSA (fPSA) measures, why it is read as a ratio to total PSA instead of one fixed normal level, and what a raised result can mean.
- HE4 Test Explained: Ovarian Cancer MarkerWhat the HE4 blood test shows, why it is most often done together with CA 125 in already diagnosed or suspected ovarian cancer, and what a raised result means.
- PSA Test Explained: Normal Range & ResultsWhat the PSA test measures, the normal limit of 4.0 ng/ml per MedlinePlus, why a raised result usually is not cancer, and what a doctor checks next.
- ROMA Index Explained: HE4 and CA 125 CombinedWhat the ROMA index is, how it is calculated from HE4, CA 125 and menopausal status, and why a higher value is a likelihood rather than a diagnosis.
- S100 (S100B) Test: What the Result MeansWhat the S100 (S100B) blood test shows, why it is used mainly to follow melanoma treatment, and why one result is never read on its own.
Autoimmune and allergy10
- AMA-M2 Antibodies Test: What a Positive MeansWhat the AMA-M2 antibodies test shows, why it is done alongside ASMA and ANA, and how a positive or a negative result is read.
- ANA Test Explained: Antinuclear AntibodiesWhat the ANA test shows, how the titre is reported, what a positive result can mean and why a doctor reads it together with symptoms.
- ANCA Test Explained: Positive and Negative ResultsWhat the ANCA test shows, why the result is positive or negative rather than a number, and what a positive result can mean.
- Anti-CCP Test: What the Result MeansWhat an anti-CCP test shows, what a positive or negative result means per MedlinePlus, and why it is usually read together with rheumatoid factor.
- Anti-DGP Test Explained: Coeliac AntibodiesWhat the anti-DGP antibody test shows when coeliac disease is suspected, why gluten must not be avoided beforehand, and how the result is read.
- Anti-dsDNA Test Explained: Lupus AntibodiesWhat the anti-dsDNA antibody test shows when lupus is suspected, why it is done alongside ANA, and how a positive result is read.
- Anti-tTG IgA Test Explained: Coeliac AntibodiesWhat the anti-tTG IgA antibody test shows when coeliac disease is suspected, why gluten must not be avoided beforehand, and how the result is read.
- Anticardiolipin Antibodies Test Explained (aCL)What the anticardiolipin antibodies (aCL) test shows when antiphospholipid syndrome is suspected, and how a positive result is read.
- IgE Blood Test (Immunoglobulin E): What It ShowsWhat the total and the specific IgE (immunoglobulin E) blood test shows, when a doctor orders it, and what a raised result can mean, per MedlinePlus.
- Rheumatoid Factor Test: Normal Range & ResultsWhat the rheumatoid factor (RF) test shows, what a negative result means per MedlinePlus, and why a positive RF alone does not mean rheumatoid arthritis.
Bone metabolism4
- Beta-CrossLaps (CTX) Test ExplainedWhat the Beta-CrossLaps (β-CTX) blood test measures, why it is used to follow osteoporosis treatment, and what a raised or lowered result can mean.
- Bone Alkaline Phosphatase (BALP) Test ExplainedWhat the bone alkaline phosphatase (BALP) test shows, why it has no separate standardised reference range, and what a raised or a low result can mean.
- Osteocalcin Test ExplainedWhat the osteocalcin blood test measures, why there is no single normal range for it, and what a raised or lowered result can mean.
- TRAP Test Explained: Bone Resorption MarkerWhat the TRAP (tartrate-resistant acid phosphatase) blood test shows, why no single normal range was found for it, and who orders it.
Urine tests6
- 24-Hour Urine Creatinine Test: Normal RangeWhat creatinine in 24-hour urine measures, the MedlinePlus range for adults, and what a reduced or a raised result can mean.
- Urinalysis Explained: Normal Ranges & ResultsWhat a urinalysis checks — urine pH 4.6-8.0 and specific gravity 1.005-1.030 — and what glucose, protein, nitrites or blood in the urine can mean.
- Urine Albumin Test: Normal Range & ResultsWhat the urine albumin test measures, the MedlinePlus normal range of under 30 mg/g creatinine, and what microalbuminuria and macroalbuminuria mean.
- Urine Creatinine Test: Normal Range & ResultsWhat urine creatinine shows, the MedlinePlus normal range of 500–2,000 mg (4.4–17.7 mmol) a day in a 24-hour collection, and what a high or low result can mean.
- Urine Protein Test: Normal Range & ResultsWhat a urine protein test measures, the MedlinePlus normal range of 0–14 mg/dl in a random sample and 30–150 mg per day, and what a raised result means.
- Urine Sediment Test: Normal Range & ResultsWhat urine sediment microscopy counts, the MedlinePlus norm of up to 4 red blood cells per field of view, and what a raised result can mean.
Infections4
- Chlamydia Test: What a Positive Result MeansWhat the chlamydia test looks for, how the sample is taken, who should be tested and what a positive or negative result means.
- Cytomegalovirus Test (CMV): What the Result MeansWhat a cytomegalovirus (CMV) blood test shows, when it is done in pregnancy and for newborns, and what a positive result means.
- Gonorrhea Test: What a Positive Result MeansWhat the gonorrhea test looks for, how the sample is taken, who should be tested and what a positive or negative result means.
- Toxoplasmosis Test Explained: What Results MeanWhat a toxoplasmosis blood test shows, when it is done in pregnancy or with weakened immunity, and what a positive result means.
This site is not an emergency service. If severe chest or head pain, breathlessness, confusion, difficulty speaking, heavy bleeding or another acute problem has come on suddenly — do not wait for tests, call 112.
This information is not a diagnosis and does not replace a consultation with a doctor. Reference ranges depend on the laboratory, your age and sex — always compare your result with the range printed on your own report.
Frequently asked questions
›What will I find on a marker page?
What the marker measures, when a doctor orders it, how to prepare, the reference ranges with their source, what a raised and a low result mean, the most common causes, and what is worth discussing with a doctor.
›How do I find my marker?
Markers are grouped into categories — thyroid, lipids, liver, kidneys, iron, vitamins and others. Search by the name or the abbreviation on your result sheet, for example TSH, ALT, ferritin or MCV.
›What should I do if a marker is outside the reference range?
A single value outside the range does not in itself mean disease: the result is affected by preparation, the time of day, medicines and temporary conditions. It is worth discussing the result with a doctor, who assesses it together with other tests and your symptoms.
›Are marker reference ranges the same for men, women and children?
Not always. For some markers, such as haemoglobin, ferritin or testosterone, the limits differ by sex, age or pregnancy.
›How often is the content updated?
Each page shows the date it was last updated, and each source shows when it was last accessed. When a source or a guideline changes, the page is corrected and the date is updated.