You have the report in your hand and no idea what it means. Here is what the common numbers stand for, why one value outside the range is usually not a problem, and when to actually worry.
You collect your blood test report, look at a page of numbers and short forms, and find one value printed in bold with an arrow next to it. Most people go straight to the internet and frighten themselves.
Here is what those numbers actually mean, in plain English.
First, understand the “normal range”
Every value on your report is printed next to a range. That range is not a line between healthy and sick. It is simply the range that covers most healthy people — and “most” is not “all”.
Two things follow from that.
Ranges differ slightly between laboratories, because they use different machines and methods. So always read your result against the range printed on your own report, not one you found online.
And a value sitting just outside the range is common and often means nothing at all. What matters is how far outside it is, whether it is changing over time, and how you actually feel. That is why a report belongs in a doctor’s consultation and not in a search box.
Haemoglobin (Hb)
Haemoglobin is what carries oxygen around your body. When it is low, less oxygen reaches your tissues — which is why the main symptom of low haemoglobin is tiredness, along with breathlessness on stairs and looking pale.
Broadly, about 13 g/dL and above is normal for adult men, and about 12 g/dL and above for non-pregnant adult women. Thresholds are different in pregnancy and in children.
Low haemoglobin is called anaemia, and in India the commonest cause by far is lack of iron. But finding out why iron is low matters just as much as correcting it. You can read more on our anaemia page.
White blood cells (WBC or TLC)
These are your infection-fighting cells. A raised count often means your body is fighting an infection. A low count has several possible causes, including certain viral infections and some medicines.
This number moves around a lot for ordinary reasons, so a single slightly high or low value is rarely meaningful on its own.
Platelets
Platelets help your blood to clot. Most people first hear about them during dengue, when the count is watched closely.
Doctors read the platelet count together with your symptoms and other results, never alone. A low number in someone who is alert, drinking and passing urine normally is a very different situation from the same number in someone with warning signs.
Blood sugar and HbA1c
Fasting blood sugar is a snapshot of your glucose at that moment, after eight to ten hours without food. Below 100 mg/dL is normal, 100 to 125 is prediabetes, and 126 or above on two occasions suggests diabetes.
HbA1c is different and more useful. It reflects your average blood sugar over about three months, so it cannot be fixed by eating carefully for two days before the test. Below 5.7% is normal, 5.7 to 6.4% is prediabetes, and 6.5% or above suggests diabetes.
More detail is on our blood sugar test page and our type 2 diabetes page.
Creatinine and eGFR
Creatinine is a waste product your kidneys filter out. When the level rises, it can mean the kidneys are not filtering as well as they should.
But creatinine also rises for harmless reasons — dehydration, heavy exercise the day before, a large meat meal, or certain medicines. Muscular people naturally have higher creatinine than others.
eGFR is an estimate of how well the kidneys are filtering. Higher is better. Doctors normally repeat an abnormal result and check urine before concluding anything. See our kidney function test page.
Cholesterol (lipid profile)
Your report will show total cholesterol, LDL, HDL and triglycerides.
LDL is often called the “bad” one — lower is generally better. HDL is the “good” one — higher is generally better. Triglycerides rise with alcohol, sugar, refined carbohydrates and uncontrolled diabetes.
Here is the important part: there is no single target that applies to everybody. The level your doctor wants for you depends on your overall risk of heart disease — your blood pressure, whether you have diabetes, whether you smoke, your age and your family history. Two people with the same LDL can be given completely different advice, and both can be right. See our lipid profile page.
Liver tests (SGPT, SGOT, bilirubin)
SGPT and SGOT are enzymes from liver cells. Raised levels suggest the liver is irritated or inflamed. Mildly raised values are very common, and fatty liver is a frequent cause.
Bilirubin is what turns the skin and eyes yellow in jaundice when it builds up. See our liver function test page.
Thyroid (TSH)
TSH is the main thyroid screening test, and it works in a way that confuses people: a high TSH usually means an underactive thyroid.
The reason is that TSH is not made by the thyroid. It is the signal your brain sends telling the thyroid to work. When the thyroid is not producing enough, the brain sends a louder signal — so the TSH number goes up. See our hypothyroidism page.
Three things worth remembering
- One value slightly outside the range is usually not a problem. Trends over time matter more than single readings.
- Do not diagnose yourself from a report. The same number means different things in different people.
- Be careful with “full body checkup” packages. They test many things that are not useful in someone without symptoms, and mildly abnormal results in healthy people often lead to more tests and more worry rather than better health.
Take your report to a doctor, and take your previous reports too. The comparison usually tells them more than any single page.