Blood values by body system

ALT (Alanine Aminotransferase)

Your ALT value shows how much alanine aminotransferase is in your blood. This enzyme sits mainly in the liver. That makes ALT the most liver-specific of the routine enzymes. When it reaches the blood, liver cells have been damaged. In adult men the reference range runs to 45 u/l, and in women to 34 u/l. A mildly raised result is common and has several causes. Fatty liver leads that list, well ahead of alcohol and hepatitis.

9-71 8-52 u/l

AST (Aspartate Aminotransferase)

Your AST value shows how much aspartate aminotransferase is circulating in your blood. It is an enzyme that leaks out whenever cells are damaged. AST sits in the liver, but equally in skeletal muscle, heart muscle, kidneys, brain and red blood cells. That is why a raised AST is not, on its own, a liver value. A hard training session the day before explains the result more often than liver disease does. The reference range runs up to 35 u/l in men and 31 u/l in women. What the number means only becomes clear alongside ALT, gamma-GT and CK.

14-53 12-49 u/l

Vitamins

Active Vitamin B12

Active Vitamin B12 measures the bioavailable form of vitamin B12 that your body can readily use. Unlike total B12, this test may provide a more accurate picture of your actual B12 status and cellular availability.

35-108 35-108 pmol/l

Albumin

Albumin is the most abundant protein in the blood, produced by the liver. It maintains fluid balance, transports hormones and nutrients, and serves as an indicator of liver and kidney function.

30-52 31-51 g/l

Cardiovascular

ApoB (Apolipoprotein B)

Apolipoprotein B (ApoB) is the main protein on LDL and other atherogenic lipoproteins. Each atherogenic particle carries exactly one ApoB molecule, making it a precise measure of the total number of particles that can contribute to plaque formation.

Bilirubin (Direct)

Direct (conjugated) bilirubin is the water-soluble form of bilirubin that has been processed by the liver. Elevated levels may indicate bile duct obstruction or liver disease and are an important component of liver function assessment.

< 5 < 5 umol/l

Bilirubin (Indirect)

Indirect bilirubin is the part of your bilirubin that your liver has not yet processed. The value is not measured separately but calculated: your total bilirubin minus your direct bilirubin, in the same unit. That split helps to show where an abnormal total is coming from. This page explains what your indirect bilirubin result can mean.

Bilirubin (Total)

Total bilirubin measures the combined amount of direct and indirect bilirubin in your blood. Bilirubin is a waste product formed during the normal breakdown of red blood cells, and elevated levels may indicate liver disease, bile duct problems, or increased red blood cell destruction.

2-29 2-22 umol/l

Inflammation

CRP (C-Reactive Protein)

C-Reactive Protein (CRP) is a protein produced by the liver in response to inflammation. It is a general marker of inflammation and can rise rapidly during infections, injuries, or chronic inflammatory conditions.

< 10 < 10 mg/l

Cardiovascular

Cholesterol/HDL Ratio

The cholesterol/HDL ratio is your total cholesterol divided by your HDL. The number summarises how your favourable and unfavourable cholesterol relate to each other. A lower ratio points to a more favourable profile and a lower cardiovascular risk. Learn what your value can mean.

< 5 < 5 mol/mol

Cortisol

Cortisol is the body's primary stress hormone, produced by the adrenal glands. It regulates metabolism, immune responses, and the sleep-wake cycle. Levels follow a natural daily rhythm, peaking in the morning and declining throughout the day.

133-537 133-537 nmol/l

Kidney

Creatinine

Creatinine is a waste product that is continuously produced in your muscles. The kidneys filter it out of the blood and remove it in urine. The blood creatinine level is therefore a core number for kidney function. In Dutch it is written both as creatinine and as kreatinine. Because production depends on your muscle mass, the same figure reads differently per person. A raised creatinine does not automatically point to a kidney problem. This page explains what high and low values can mean. It also covers the everyday things that shift the result temporarily.

38-149 38-132 umol/l

Inflammation

ESR (Erythrocyte Sedimentation Rate)

Your ESR result shows how quickly red blood cells settle towards the bottom of an upright tube. The laboratory reads that distance after exactly one hour, in millimetres per hour. Normally the cells drift down slowly. During inflammation certain proteins in the blood rise. Those proteins make the cells stack together. The red cells then fall faster, and the result reads higher. So the ESR does not measure inflammation directly. It measures a physical consequence of it. That distinction shapes how the result should be read.

< 15 < 20 mm/h

Estradiol (E2)

Estradiol (E2) is the most potent form of estrogen, playing a key role in reproductive health, bone density, and cardiovascular function. Abnormal levels may indicate hormonal imbalances that your healthcare provider can help evaluate.

41-159 46-607 pmol/l

FSH (Follicle Stimulating Hormone)

Follicle-stimulating hormone (FSH) is produced by the pituitary gland and plays an essential role in reproductive function. It regulates egg development in women and sperm production in men. Abnormal levels may indicate changes in fertility or hormonal health.

1.5-12.4 U/L

Minerals

Ferritin

Ferritin is a protein that stores iron, so your ferritin level shows how large your iron reserve is. Serum iron only measures how much iron is circulating in your blood at that moment; ferritin describes the reserve behind it. That reserve empties before your haemoglobin falls, so a low ferritin can already cause symptoms while your blood count still looks normal. Ferritin also rises with inflammation, infection and liver strain, which is why it can only be read properly alongside a CRP. Commonly used reference values are 30 to 400 µg/l for men and 15 to 150 µg/l for women, but your own laboratory report is what counts.

30-400 15-150 ug/l

Vitamins

Folate (Folic Acid)

Folate, also known as vitamin B9, is a water-soluble vitamin involved in cell division and DNA synthesis. Adequate folate levels are considered important for overall health and may be particularly relevant during periods of rapid growth.

10-42 10-42 nmol/l

Thyroid

Free T3 (Triiodothyronine)

Free T3 (triiodothronine) is considered the most active thyroid hormone. It may play a key role in regulating metabolism, energy production, and body temperature. Healthcare providers often assess Free T3 alongside other thyroid markers for a comprehensive picture.

3.1-6.8 3.1-6.8 pmol/l

Thyroid

Free T4 (Thyroxine)

Free T4 (thyroxine) is the main hormone produced by the thyroid gland. It may serve as a precursor that your body converts into the more active T3. Healthcare providers often consider Free T4 a primary indicator of thyroid gland output.

12-22 12-22 pmol/l

Free Testosterone

Free testosterone is the unbound, bioavailable form of testosterone that can directly enter cells and activate receptors. It may indicate your body's functional androgen activity. Your healthcare provider can help interpret what your levels mean.

170-700 3-29 pmol/L

GGT (Gamma-Glutamyl Transferase)

GGT (gamma-glutamyl transferase) is a liver and bile duct enzyme that serves as one of the most sensitive markers for hepatobiliary disorders. It is particularly responsive to alcohol consumption and may be elevated in bile duct obstruction, liver disease, and with certain medications.

< 55 < 38 u/l

Metabolic

Glucose (Fasting)

Fasting glucose measures the level of sugar (glucose) in your blood after an overnight fast. It is one of the primary tests used to screen for and monitor diabetes and pre-diabetes.

3.5-5.5 3.5-5.5 mmol/l

Cardiovascular

HDL Cholesterol

HDL cholesterol is the amount of cholesterol carried inside the HDL particles in your blood. Those particles pick cholesterol up from your tissues and from the artery wall and take it back to the liver. That transport is what earned HDL the nickname good cholesterol. The nickname is misleading. HDL is above all a mirror of your metabolism: the value drops with excess weight, insulin resistance, smoking and inactivity, and it is those factors that carry the risk. Drugs that raise HDL substantially do not reduce the number of cardiovascular events. And more is not always better: at very high values, mortality in large population studies turns back upwards. So never read your HDL on its own. It only takes on meaning alongside your triglycerides, your LDL and your overall risk profile.