What blood tests should I do for unexplained fatigue?

CBC, Ferritin, Vitamin B12, Vitamin D3, TSH, Free T3, Anti-TPO, HbA1c, Fasting Glucose, AM Cortisol. Together these detect iron deficiency, B12 deficiency, vitamin D deficiency, thyroid disease, autoimmune thyroid, diabetes, and adrenal issues — the seven most common medical causes of fatigue.

Why test ferritin if my haemoglobin is normal?

Iron stores fall before haemoglobin drops — ferritin is the early marker of iron deficiency. Fatigue, hair loss, and brain fog are common with low ferritin even when haemoglobin is technically normal. Especially common in Indian women.

Can low Vitamin D cause fatigue?

Yes — Vitamin D deficiency is a recognised cause of fatigue, muscle weakness, and low mood. 70–80% of urban Indians are deficient. Correction with supplementation usually improves energy within 2–3 months.

Why test thyroid if my TSH was normal last year?

Thyroid disease can develop quickly. Subclinical hypothyroidism (TSH 4–10) is also common in Indians and often dismissed. Free T3 and Anti-TPO may reveal disease that TSH alone misses. Repeat thyroid panel if symptoms persist despite previously normal TSH.

What's the cost of a complete fatigue workup?

Individual tests: ₹50–800 each. Fatigue Workup Package: typically ₹3,500–5,000 at Gini. Many insurance plans cover when fatigue persists despite treatment.

What if all my fatigue tests are normal?

Consider sleep apnoea (especially if snoring or BMI elevated), depression/anxiety, chronic fatigue syndrome, fibromyalgia, or under-recognised sleep disturbance. Specialist evaluation by Internal Medicine, Psychiatry, or Sleep Medicine is appropriate.

Blood Tests for Fatigue — The Complete Indian Workup

The Complaint

"I'm Always Tired" — The Most Common Patient Complaint

Tiredness is the single most common reason patients see their doctor. Most are told "your tests are normal, get more sleep." This often misses the actual cause.

Genuine fatigue with a medical cause can usually be explained by one of seven common conditions — each detected by a specific test. This is the structured fatigue workup.

Full Panel

The Complete Fatigue Workup

Test	Price	Why You Need It
CBC →	₹350	Anaemia — the #1 cause of fatigue in Indian women
Ferritin →	₹500	Iron stores — falls before haemoglobin
Vitamin B12 →	₹600	Especially vegetarians and metformin users
Vitamin D3 →	₹800	70–80% urban Indians deficient
TSH →	₹200	Thyroid screening — very common cause
Free T3 →	₹150	Active thyroid hormone — even with normal TSH
Anti-TPO →	₹600	Hashimoto's — common Indian cause
HbA1c →	₹350	Diabetes/pre-diabetes can cause fatigue
Fasting Glucose →	₹50	Hypoglycaemia or hyperglycaemia
Cortisol →	₹600	Adrenal function — AM cortisol

Interpretation

How to Interpret Common Findings

Low haemoglobin OR low ferritin (even with normal Hb): Iron deficiency. Fatigue + hair loss + brain fog all common. Treatable.
Low B12: Vegetarians, metformin users. Causes fatigue, tingling, brain fog. Easily treated with supplementation.
Low Vitamin D: Almost universal in urban Indians. Contributes to fatigue, muscle weakness, low mood.
TSH 4–10: Subclinical hypothyroidism — common Indian finding, often dismissed but causes real symptoms.
Anti-TPO positive: Hashimoto's. May progress to hypothyroidism — monitor.
HbA1c 5.7–6.4: Pre-diabetes can cause unstable energy and fatigue.
Low morning cortisol: Adrenal insufficiency — rare but important. Specialist evaluation needed.