How to Read Your Blood Test Report: A Complete Guide for India

You got your blood test report. It is a page (or three) of numbers, abbreviations, reference ranges, arrows, and asterisks. Your doctor glanced at it for 90 seconds. You have been staring at it for 20 minutes.

This guide is for that second group. We will walk through every section of a typical Indian blood test report - what each value measures, what high or low means, how to read the flags, and how to decide what actually needs follow-up.

Part 1: The Anatomy of a Blood Test Report

Before diving into values, let us understand what a report looks like.

What You Will Always See

Test name: What was measured (e.g., "Haemoglobin", "TSH", "LDL Cholesterol")

Your result: The measured value with its unit (e.g., "11.2 g/dL", "4.5 mIU/L")

Reference range: The expected range for healthy adults, sometimes broken down by age or sex (e.g., "12.0 - 15.0 g/dL for women")

Flag: Most labs use H (High), L (Low), or symbols like * or ! for critically abnormal values

Units: Different tests use different units - g/dL, mg/dL, mIU/L, U/L, µ/L, pg/mL, and more. Never compare a number across different units.

Why Reference Ranges Differ Between Labs

Different labs use different equipment, reagents, and population calibrations. A "normal" TSH range at Dr Lal PathLabs may differ slightly from SRL or Thyrocare. This is normal and expected. Always compare your result to the reference range printed on your own report - never to a number you found on a different lab's website or an online forum.

Part 2: The Most Common Blood Test Panels

Complete Blood Count (CBC)

The most frequently ordered test in India. It measures the cells in your blood.

Haemoglobin (Hb): Oxygen-carrying protein in red cells. Low = anaemia. High = dehydration or polycythaemia. Normal: Men 13-17 g/dL, Women 12-15 g/dL.

RBC Count: Number of red cells. Mirrors haemoglobin - low in anaemia, high in polycythaemia.

Haematocrit (PCV): Percentage of blood volume that is red cells. Follows haemoglobin trends.

MCV: Average size of red cells. Low MCV = iron deficiency or thalassaemia. High MCV = B12 or folate deficiency.

MCH / MCHC: Haemoglobin content per cell. Low = iron deficiency or thalassaemia.

RDW: Variation in red cell sizes. High RDW = mixed deficiency or early iron/B12 deficiency.

WBC (Total Leucocyte Count): Total white cells. High = infection, inflammation, or steroid use. Low = viral infection (especially dengue), medication, or bone marrow issue. Normal: 4,000-11,000/µL.

Neutrophils: First responders to bacterial infection. % of total WBC. Normal: 40-70%.

Lymphocytes: Viral immunity. Normal: 20-40%. High in viral infections.

Eosinophils: Allergy and parasitic infections. Normal: 1-4%. Commonly high in India due to allergies and parasites.

Platelets: Blood clotting cells. Normal: 1.5-4.0 lakh/µL. Low in dengue, viral infections, liver disease.

Kidney Function Test (KFT / RFT)

Creatinine: Muscle waste product filtered by kidneys. High = kidneys filtering less efficiently, or dehydration, or high-protein diet. Men: 0.7-1.2 mg/dL, Women: 0.5-1.0 mg/dL.

eGFR (Estimated GFR): Calculated from creatinine, age, sex. Tells you what percentage of kidney function you have. Below 60 = reduced kidney function.

Blood Urea Nitrogen (BUN) / Blood Urea: Another waste product. High with dehydration, high protein diet, or kidney disease. Normal: 7-20 mg/dL (BUN) or 15-45 mg/dL (urea).

Uric Acid: Purine metabolism waste. High = gout risk or kidney stress. Men: 3.4-7.0 mg/dL, Women: 2.4-6.0 mg/dL.

Electrolytes (Sodium, Potassium, Chloride): Sodium: 136-145 mEq/L. Potassium: 3.5-5.0 mEq/L. Critical for heart rhythm - very high or very low potassium is a medical emergency.

Liver Function Test (LFT)

SGPT (ALT): Liver-specific enzyme. High = liver stress, fatty liver, hepatitis. Normal: 7-56 U/L.

SGOT (AST): Also in heart and muscles - less liver-specific than SGPT. Normal: 10-40 U/L.

Alkaline Phosphatase (ALP): Elevated in bile duct problems, bone disease, liver disease. Normal (adults): 44-147 U/L.

GGT (Gamma-GT): Sensitive to alcohol and liver disease. Often elevated in fatty liver and alcohol use.

Total Bilirubin: Waste product from red cell breakdown, processed by the liver. High = jaundice or liver disease. Normal: 0.3-1.2 mg/dL.

Albumin: Protein made by the liver. Low = poor liver function or malnutrition. Normal: 3.5-5.0 g/dL.

Total Protein: Sum of all blood proteins. Normal: 6.0-8.3 g/dL.

Lipid Panel (Fasting)

Total Cholesterol: Below 200 mg/dL desirable.

LDL Cholesterol: "Bad" cholesterol. Below 100 mg/dL optimal; below 130 acceptable.

HDL Cholesterol: "Good" cholesterol. Above 60 mg/dL protective. Below 40 (men) or 50 (women) is a risk factor.

Triglycerides: Below 150 mg/dL normal. Driven more by carbohydrate intake than dietary fat.

Non-HDL Cholesterol: All bad cholesterol combined. Better predictor of heart risk than LDL alone.

Thyroid Function Test (TFT)

TSH (Thyroid Stimulating Hormone): The first-line test. High TSH = hypothyroidism (underactive thyroid). Low TSH = hyperthyroidism (overactive thyroid). Normal: 0.4-4.0 mIU/L.

Free T4 (FT4): Main thyroid hormone. Used alongside TSH. Low FT4 with high TSH confirms hypothyroidism.

Free T3 (FT3): Active form of thyroid hormone. Usually tested when TSH/T4 are abnormal.

Diabetes Panel

Fasting Blood Glucose: Blood sugar after 8+ hours fast. Below 100 mg/dL normal. 100-125 = prediabetes. 126+ = diabetes (if confirmed on repeat).

HbA1c: 3-month average blood sugar. Below 5.7% normal. 5.7-6.4% prediabetes. 6.5%+ diabetes.

Post-Prandial Glucose (PPBS): Blood sugar 2 hours after a standard meal. Below 140 mg/dL normal. 140-199 = prediabetes. 200+ = diabetes.

Nutrition Tests

Vitamin D (25-OH): Below 20 ng/mL deficient. 20-30 insufficient. 30-60 normal. Deficiency extremely common in India.

Vitamin B12: Below 200 pg/mL deficient. 200-300 borderline. 300-900 normal. Very common deficiency in vegetarians.

Serum Iron / Ferritin: Iron = how much is circulating. Ferritin = how much is stored. Low ferritin is the earliest sign of iron depletion - often falls before haemoglobin drops.

Part 3: How to Read the Flags

One flag in isolation is rarely an emergency. What matters is the pattern - multiple related values outside range together, a single value critically elevated, or a known normal value that has shifted significantly.

Part 4: What the Degree of Abnormality Means

A value 5% outside the reference range is very different from one that is 300% above it. Here is a general guide:

Borderline (just outside the range): Often not clinically significant on its own. Repeat in 4-8 weeks. Watch for symptoms.

Mildly abnormal (10-30% outside range): Worth investigating the cause. A pattern with other values may tell a clearer story.

Significantly abnormal (more than 50% outside range, or critically flagged): Act on this. See a doctor within days, not weeks.

Any critically flagged value (!! or critical flag): Act the same day or go to a clinic or emergency room depending on symptoms.

Part 5: Common Questions When Reading a Report

"Several things are flagged - how do I prioritise?" Focus on: (1) any critical flags first, (2) values significantly outside range, (3) clusters of related values that tell a story together (e.g., low Hb + low MCV + low ferritin = iron deficiency).

"My result is 'normal' but I feel unwell." Reference ranges are statistical averages from a population. Some people feel best at the higher or lower end of a normal range. Symptoms combined with borderline-normal values are worth discussing with your doctor - especially for thyroid (TSH can be "normal" but suboptimal for some people) and B12.

"The results look different from a test I had last year." Different labs use different equipment. The actual value may shift between labs even without any real change in health. A 10-15% variation between labs for the same sample is not unusual for some tests.

"My doctor says not to worry, but I am worried." This guide helps you understand what you are looking at, but it cannot replace your doctor's clinical knowledge of your full history. If you want more clarity, ask your doctor specifically: "Is this value stable or trending in a concerning direction?" and "What should I watch for that would prompt me to call you?"

Part 6: Building a Health Baseline

The most valuable thing you can do with a blood test is track it over time. A creatinine of 1.2 mg/dL at 35 is your baseline. If it is 1.6 mg/dL at 40 with no change in lifestyle, that trend matters more than either individual number.

Store your reports digitally. Take a photo or scan every report. Note the date, lab, and any relevant context (fasting, medication, illness at the time).

Must Read

• Understanding Your CBC Results: High and Low Values - A deeper dive into every CBC value and what each high/low flag means
• Annual Health Checkup Guide India - What tests to include at each age, how to prepare, and how to get the most from your checkup

Try ReportSense on your own report. ReportSense reads your entire blood test report, explains every value in plain language, flags patterns across multiple values, tracks trends across visits, and generates specific questions for your doctor - all in minutes. Try it free at reportsense.in.