Lab test results explained

Plain-English guides to the blood tests people get most often, with typical reference ranges, the common reasons a result is high or low, and when to get help. Every page is reviewed by Dr Husain Farooq, a medical doctor and biochemistry educator who works in clinical pathology.

Check your report

CBC Report Explainer

Enter your blood count and see which values sit outside the range.

Thyroid Report Explainer

Check TSH, free T4 and free T3 against the reference range.

HbA1c Calculator

HbA1c % ↔ mmol/mol and estimated average glucose (eAG).

eGFR Calculator

Kidney function (CKD-EPI 2021) from creatinine, age and sex.

Blood Sugar Converter

Convert glucose between mg/dL and mmol/L with normal ranges.

Lab Unit Converter

Convert lab results between US units and SI units.

All lab tests

Complete Blood Count (CBC)

The CBC is the most common blood test in the world. It checks your red cells, white cells and platelets in one sample.

Thyroid Function Test (TFT)

A thyroid profile checks how well your thyroid gland is working by measuring TSH and the thyroid hormones.

HbA1c Test

HbA1c shows your average blood sugar over the last two to three months. It is used to diagnose diabetes and track control.

Blood Glucose (Sugar) Test

Blood glucose tests measure the sugar in your blood at one moment. Fasting, random and 2-hour tests each have their own cut-offs.

Lipid Profile (Cholesterol Test)

A lipid profile measures the fats in your blood that affect heart and stroke risk.

Liver Function Test (LFT)

An LFT is a group of blood tests that look for liver cell damage, bile flow problems and how well the liver is making protein.

Vitamin D Test (25-OH)

The 25-OH vitamin D test shows your body's vitamin D stores. Low levels are very common, even in sunny countries.

Kidney Function Test (KFT / RFT)

A kidney function test checks how well your kidneys are filtering waste and balancing salts in your blood.

How to read a lab report

Each result on your report sits next to a reference range, usually the middle 95% of healthy people tested by that lab. A value just outside the range is common and often not significant: about 1 in 20 healthy people fall outside any single range. What matters is how far a value is from the range, whether several results point the same way, and how you feel.

Ranges also vary between labs because of different machines and methods, and they change with age, sex and pregnancy. Always use the range printed on your own report, and talk to your doctor before acting on a result.

Our pages are general information, not a diagnosis. Read our medical editorial policy.