How to read your blood test report: TSH, HbA1c, SGOT and more

Most blood test reports look intimidating: rows of acronyms, numbers, and asterisks next to anything outside the reference range. This guide walks through the markers that show up most often on Indian lab reports, in plain language. It is not medical advice — always discuss your specific results with a qualified doctor.

Quick reference: common blood test ranges

Marker	Typical adult range	What it tells you
TSH (thyroid)	0.4 – 4.0 mIU/L	Thyroid function
HbA1c (3-month sugar)	< 5.7%	Long-term blood sugar
Fasting glucose	70 – 99 mg/dL	Sugar after 8+ hrs fasting
SGPT / ALT	7 – 56 U/L	Liver cell health
SGOT / AST	10 – 40 U/L	Liver & muscle health
Total cholesterol	< 200 mg/dL	Overall lipid health
LDL ("bad" cholesterol)	< 100 mg/dL	Heart-disease risk marker
HDL ("good" cholesterol)	> 40 (M) / > 50 (F) mg/dL	Protective lipid
Triglycerides	< 150 mg/dL	Stored fat in blood
Vitamin D (25-OH)	30 – 100 ng/mL	Bone & immune health
Vitamin B12	200 – 900 pg/mL	Nerve & blood-cell health
Creatinine	0.7 – 1.3 (M) / 0.6 – 1.1 (F) mg/dL	Kidney function
Haemoglobin	13.5 – 17.5 (M) / 12.0 – 15.5 (F) g/dL	Oxygen-carrying capacity

Reference ranges vary slightly between labs — always read the range printed on your own report.

TSH — thyroid stimulating hormone

TSH is the body's signal to the thyroid gland. A high TSH usually means the thyroid is underactive (hypothyroidism) — your body is shouting at it to make more hormone. A low TSH can mean an overactive thyroid (hyperthyroidism). Symptoms of an underactive thyroid include fatigue, weight gain, hair fall and feeling cold. Overactive can mean weight loss, anxiety, racing heart.

Fasting needed? No.

HbA1c — your 3-month sugar average

HbA1c shows the average blood sugar over the past 8–12 weeks. Unlike a fasting glucose test (one moment in time), it isn't fooled by what you ate yesterday.

• < 5.7% — normal
• 5.7 – 6.4% — prediabetes
• ≥ 6.5% — diabetes range

If your HbA1c is rising year over year — even within "normal" — it's worth a conversation about diet and activity.

Fasting needed? No.

SGPT (ALT) and SGOT (AST) — liver enzymes

These two enzymes leak into the blood when liver cells are stressed or damaged. Mild elevations are very common and often reflect fatty liver, alcohol, certain medications, or recent intense exercise (AST also comes from muscle).

• Both mildly elevated (up to ~3× normal) — often lifestyle-related; recheck after diet changes.
• Sharply elevated or AST > ALT with other symptoms — your doctor will usually investigate further (hepatitis, gallbladder, alcohol-related).

Fasting needed? No, but avoid heavy exercise 24 hours before.

Lipid profile — cholesterol & triglycerides

• LDL is the cholesterol that builds up in artery walls. Lower is better.
• HDL clears cholesterol away. Higher is better.
• Triglycerides are stored fat — high values are linked to weight, sugar, and alcohol.
• Total cholesterol is roughly LDL + HDL + (Triglycerides ÷ 5).

A common scenario in Indian reports is "normal total cholesterol but high triglycerides and low HDL" — usually pointing at insulin resistance / sedentary lifestyle rather than a heart-medication conversation.

Fasting needed? Yes — 9–12 hours, water only.

Vitamin D and B12

Deficiency is extremely common in urban Indians.

• Vitamin D < 20 ng/mL is deficient; 20–30 is insufficient. Symptoms: bone pain, muscle weakness, low immunity.
• Vitamin B12 < 200 pg/mL is low. Symptoms: tingling in hands/feet, fatigue, brain fog. Strict vegetarians are at higher risk.

Fasting needed? No.

Kidney markers — creatinine & urea

Creatinine reflects how well kidneys filter waste. Your report likely also includes an eGFR number — that's the more useful one. An eGFR above 90 is normal kidney function. Below 60 for three months or more suggests chronic kidney disease and needs a doctor's review.

Fasting needed? No, but avoid heavy protein meals or supplements the day before.

Complete blood count (CBC) — the staples

• Haemoglobin (Hb) low → likely anaemia (iron, B12, blood loss).
• WBC high → often an active infection or inflammation. Low → certain viral infections or medication effects.
• Platelets low → look at recent dengue or other viral illness; very high → inflammation.

Fasting needed? No.

When should I see a doctor?

Lab software flags abnormal values with arrows or asterisks, but a single out-of-range number rarely means a diagnosis. Talk to a doctor when:

• A value is far outside the reference range (not just a tiny bit).
• A value has changed sharply from a previous report.
• You have symptoms that match the marker (fatigue, weight changes, tingling, pain).
• You have a family history of related conditions (diabetes, thyroid, heart).

How to get a reliable blood test

• Choose an NABL-accredited lab. NABL accreditation means the lab follows ISO 15189 standards and reports are widely accepted by hospitals and insurers.
• Follow fasting instructions exactly. A skipped or extended fast can shift glucose, lipid and liver numbers enough to mislabel a healthy result.
• Hydrate. Dehydration affects haemoglobin and creatinine.
• Use the same lab for follow-ups. Reference ranges vary slightly; trends are easier to read on consistent equipment.

You can find verified NABL-accredited labs near you on Locatemycentre — search by city or pincode, see addresses, and pick one that offers home sample collection if you'd rather not visit in person.

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Disclaimer: This article is for educational purposes only and is not a substitute for medical advice. Always consult a qualified doctor about your own results.