A quiet reference

Medical terms, plainly.

Plain-language definitions of common medical terms you'll see on your reports. Want a specific term explained that's not here? Use the term decoder →

Blood count

Haemoglobin (Hb / HGB)

also: Hb · HGB · Hemoglobin

The protein in red blood cells that carries oxygen around your body. Low Hb (anaemia) often causes tiredness and breathlessness.

Men: 13–17 g/dL · Women: 12–15 g/dL

WBC (White Blood Cells)

also: Leukocytes

Your immune system's fighters. High means infection or inflammation; very low can mean your body's defences are weak.

4,000–10,000 per µL

Platelets

also: PLT

Cells that clump together to stop bleeding when you cut yourself. Low platelets means easier bruising.

150,000–410,000 per µL

MCV

Mean Corpuscular Volume — the average size of your red blood cells. Small (low MCV) often points to iron-deficiency anaemia; large (high MCV) often points to vitamin B12 or folate deficiency.

83–101 fL

CBC

also: Complete Blood Count · Hemogram

The full blood count panel — measures red cells, white cells, platelets and their properties. The most common baseline blood test in India.

Composite test — see individual values

RBC

also: Red Blood Cells · Erythrocytes

The count of your red blood cells (millions per µL). Low RBC often points to anaemia; high RBC can point to dehydration or other issues.

Men: 4.5–5.9 million/µL · Women: 4.0–5.2 million/µL

MCH

also: Mean Corpuscular Hemoglobin

The average amount of haemoglobin inside each red blood cell. Low MCH often accompanies iron-deficiency anaemia.

27–33 pg

MCHC

also: Mean Corpuscular Hemoglobin Concentration

How concentrated the haemoglobin is inside each red cell. Low MCHC suggests iron-deficiency anaemia; high may suggest spherocytosis.

32–36 g/dL

RDW

also: Red Cell Distribution Width

How much your red blood cells vary in size. High RDW is an early clue to early iron, B12, or folate deficiency — often before Hb drops.

11.5–14.5%

Neutrophils

The most common type of white blood cell — first responders to bacterial infection. High neutrophils often mean bacterial infection or inflammation.

40–75% of WBCs · 2,000–7,500/µL

Lymphocytes

White cells that fight viruses and make antibodies. Rise with viral infections (COVID, dengue, flu); very low may indicate immune suppression.

20–45% of WBCs · 1,000–4,800/µL

Eosinophils

White cells that fight parasites and drive allergic responses. High eosinophils suggest allergy, asthma, worm infestation, or drug reaction.

1–6% of WBCs · <500/µL

Monocytes

Large white cells that clean up after infection or injury. Mildly elevated with chronic inflammation, TB, or recovery from infection.

2–10% of WBCs

Basophils

Rare white cells that release histamine during allergic reactions. Usually less than 1% of WBCs — rarely clinically important alone.

0–2% of WBCs

HbA1c

also: A1C · Glycated haemoglobin

Your average blood sugar over the last 2–3 months. Doctors prefer it to fasting sugar because it doesn't get fooled by what you ate that morning.

Normal: <5.7% · Pre-diabetes: 5.7–6.4% · Diabetes: ≥6.5%

Fasting Glucose

also: FBS

Blood sugar after 8+ hours without food. The basic diabetes screening test.

Normal: 70–99 mg/dL · Pre-diabetes: 100–125 · Diabetes: ≥126

PPBS

also: Post Prandial Blood Sugar · PP Glucose

Blood sugar 2 hours after a meal. Shows how well your body handles food; elevated PPBS with normal fasting is an early diabetes clue.

Normal: <140 mg/dL · Pre-diabetes: 140–199 · Diabetes: ≥200

OGTT

also: Oral Glucose Tolerance Test · GTT

A challenge test — drink 75 g glucose, measure sugar at 0, 1, and 2 hours. Standard test for gestational diabetes and unclear cases.

2h reading — Normal: <140 · Pre-diabetes: 140–199 · Diabetes: ≥200

Fasting Insulin

The amount of insulin your pancreas makes at rest. High insulin with normal sugar suggests insulin resistance (pre-diabetes territory).

2–25 µIU/mL (fasting)

LDL Cholesterol

also: LDL · Bad cholesterol

The 'bad' cholesterol — too much builds up in artery walls and raises heart disease risk.

Optimal: <100 mg/dL · Borderline: 130–159 · High: ≥160

HDL Cholesterol

also: HDL · Good cholesterol

The 'good' cholesterol — it picks up bad cholesterol and takes it to the liver to be removed.

Men: >40 mg/dL · Women: >50 · Higher is better

Triglycerides

Another kind of blood fat. Often goes up with sugary diets, alcohol, or being overweight.

Normal: <150 mg/dL · Borderline: 150–199 · High: ≥200

SGPT / ALT

also: SGPT · ALT

An enzyme inside liver cells. Elevated levels mean the liver is stressed or inflamed — common causes are fatty liver, alcohol, or medications.

10–40 U/L

SGOT / AST

also: SGOT · AST

Another liver enzyme, also found in muscles and heart. Usually rises alongside SGPT/ALT when the liver is stressed.

10–40 U/L

Bilirubin

A yellow waste product the liver clears from your blood. High levels cause jaundice (yellow skin/eyes).

Total: 0.2–1.2 mg/dL

Albumin

The main protein in your blood, made by the liver. Low albumin suggests advanced liver disease, malnutrition, or kidney protein loss.

3.5–5.0 g/dL

Total Protein

The sum of albumin + globulin in blood. Doctors use it to screen for liver, kidney, and immune problems.

6.0–8.3 g/dL

GGT

also: Gamma-Glutamyl Transferase

A liver enzyme especially sensitive to alcohol use and bile-duct problems. Often rises before other liver enzymes in early damage.

Men: 8–61 U/L · Women: 5–36 U/L

Creatinine

A waste product your kidneys filter out. High creatinine = kidneys aren't filtering well.

Men: 0.7–1.2 mg/dL · Women: 0.6–1.1 mg/dL

eGFR

also: GFR

Estimated Glomerular Filtration Rate — a calculated score of how well your kidneys filter. Higher is better.

>90 mL/min/1.73m² is healthy

Urea / BUN

also: BUN · Blood Urea Nitrogen

Another kidney-filtered waste product. Can rise with dehydration, kidney issues, or high-protein diets.

15–40 mg/dL

TSH

also: Thyroid Stimulating Hormone

A hormone from your brain that tells the thyroid how hard to work. High TSH = thyroid is sluggish (hypothyroid). Low TSH = overactive (hyperthyroid).

0.45–4.5 µIU/mL

Free T4

also: FT4

The main hormone your thyroid produces. Doctors check this alongside TSH to see what your thyroid is actually doing.

0.8–1.8 ng/dL

Ferritin

Your body's iron storage protein — think 'iron fuel tank'. Low ferritin is the earliest sign of iron deficiency, even before anaemia shows.

30–400 ng/mL

Vitamin D (25-OH)

Sunlight-vitamin, also helps absorb calcium for bone strength. Deficiency is extremely common in India, can cause fatigue and bone aches.

Sufficient: 30–100 ng/mL

Vitamin B12

Needed for healthy nerves and red blood cells. Vegetarians often run low. Symptoms include tingling, fatigue, and memory issues.

211–911 pg/mL

ESR

also: Erythrocyte Sedimentation Rate

A general inflammation marker. High ESR can mean infection, autoimmune condition, or other inflammatory process — but it's non-specific.

Men: <15 mm/hr · Women: <20 mm/hr

CRP

also: C-Reactive Protein

Another inflammation marker, more sensitive and faster-responding than ESR.

<10 mg/L (often: <3 mg/L)

Uric Acid

A waste product. Very high levels can cause gout (painful joint inflammation) or kidney stones.

Men: 3.5–7.2 mg/dL · Women: 2.6–6.0 mg/dL

PSA

also: Prostate Specific Antigen

A protein from the prostate. Elevated levels in men can mean an enlarged prostate, infection, or sometimes prostate cancer — needs context.

Typically <4 ng/mL (varies by age)

CA-125

A protein sometimes elevated in ovarian cancer, but also in endometriosis, fibroids, and pregnancy. Never diagnostic alone.

<35 U/mL

CEA

also: Carcinoembryonic Antigen

A tumour marker used mainly to monitor colon cancer treatment response. Slightly elevated in smokers and inflammatory bowel disease.

Non-smokers: <2.5 ng/mL · Smokers: <5 ng/mL

AFP

also: Alpha Fetoprotein

A protein used to screen for liver cancer, testicular cancer, and (in pregnancy) fetal neural tube defects.

Adults: <10 ng/mL

Sodium

also: Na

Main salt in your blood. Regulates fluid balance and blood pressure. Abnormal levels usually reflect hydration or kidney issues.

135–145 mmol/L

Potassium

also: K

Essential for nerve signals and heart rhythm. Both very high and very low potassium can cause dangerous heart rhythm changes.

3.5–5.0 mmol/L

Calcium

also: Ca

Needed for bones, muscle contraction, and blood clotting. Blood calcium is tightly regulated — abnormal levels are a red flag.

8.6–10.3 mg/dL (total)

Chloride

also: Cl

Works alongside sodium to balance fluids and acid-base status. Usually moves together with sodium.

96–106 mmol/L

Troponin

also: Troponin I · Troponin T · cTn

A protein released when heart muscle is damaged. Elevated troponin is a key test for diagnosing a heart attack. Every ER checks this.

<0.04 ng/mL (varies by lab)

CK-MB

also: Creatine Kinase-MB

An older heart-muscle enzyme test. Largely replaced by troponin, but still used in some Indian hospitals for acute chest pain workup.

<5 ng/mL

NT-proBNP

also: proBNP · BNP

A hormone the heart releases when it's under strain. Very high levels suggest heart failure. Used to sort breathlessness causes.

<125 pg/mL (age <75)

INR

also: Prothrombin Time Ratio · PT-INR

Measures how quickly your blood clots. Patients on blood-thinners (Warfarin/Acitrom) monitor this monthly. Higher = thinner blood.

Off medication: 0.8–1.1 · On Warfarin: 2.0–3.0

D-Dimer

A protein fragment left after a clot breaks down. High levels can suggest deep-vein thrombosis, pulmonary embolism, or recent surgery.

<500 ng/mL

ANA

also: Antinuclear Antibody

Antibodies that attack your own cell nuclei. Positive ANA is a screening test for lupus, rheumatoid arthritis, and other autoimmune diseases.

Negative (<1:80 titre)

RA Factor

also: Rheumatoid Factor · RF

An antibody often present in rheumatoid arthritis. Positive RF supports the diagnosis but can also appear in other conditions.

<14 IU/mL (negative)

HBsAg

also: Hepatitis B Surface Antigen

A blood marker showing active Hepatitis B infection. A positive test means the virus is present — requires specialist follow-up.

Negative / Non-reactive

⚠️ These definitions are simplified for understanding. Normal ranges vary slightly by lab and demographic. Always follow your doctor's interpretation of your specific report.

Blood count

Diabetes

Lipid profile

Liver

Kidney

Thyroid

Iron / Vitamins

Inflammation

Metabolism

Cancer screening

Electrolytes

Cardiac

Clotting

Autoimmune

Viral

Blood count

Diabetes

Lipid profile

Liver

Kidney

Thyroid

Iron / Vitamins

Inflammation

Metabolism

Cancer screening

Electrolytes

Cardiac

Clotting

Autoimmune

Viral