What this test measures
Haemoglobin is the iron-containing protein inside red blood cells that carries oxygen from your lungs to every tissue and returns carbon dioxide. A Hemoglobin test reports the concentration in grams per decilitre (g/dL) — the standard unit used by Indian labs.
The value depends on (a) how many red cells you have and (b) how much haemoglobin is packed into each one. Both axes can be off in disease — and reading haemoglobin alongside CBC indices (MCV, MCH, RDW) tells you whether anemia is iron-deficient (low MCV / MCH), megaloblastic (high MCV), or normocytic (normal MCV — chronic disease, kidney disease).
Why it matters
India has one of the highest rates of anemia in the world — roughly 57% of women aged 15–49 and 25% of men have anemia per the National Family Health Survey. Anemia is silent for a long time: persistent low-grade fatigue, breathlessness on exertion, pallor and reduced exercise tolerance are easily blamed on lifestyle. Untreated anemia in pregnancy increases the risk of low birth weight, prematurity, and maternal mortality.
A haemoglobin test is the cheapest, fastest screen for anemia and is recommended annually for all adults, every trimester in pregnancy, and any time symptoms of anemia appear. Once anemia is detected, follow-up tests (Iron Studies, Ferritin, B-12, Folate, peripheral smear) identify the cause so the right treatment can be started.
How to prepare
No fasting required. The test can be done any time of day. Hydrate normally — severe dehydration can transiently raise haemoglobin, and over-hydration can lower it. If you have recently donated blood or had a major bleed, mention it so the lab knows your baseline is unusually low.
Markers & reference ranges
Reference ranges below are typical adult values. Your lab's reported range may differ slightly based on the assay platform and patient demographics — always read your report against the range printed on it.
| Marker | Normal range | If low | If high |
|---|---|---|---|
| Haemoglobin (Hb) (g/dL)[1][2] | Men 13.0–17.0 · Non-pregnant women ≥12.0 · Pregnant women ≥11.0 · Children 12–14 yrs ≥12.0 | < 13 in men, < 12 in non-pregnant women, < 11 in pregnant women = anemia. Severity: 11–11.9 (women) / 11–12.9 (men) = mild; 8–10.9 = moderate; < 8 = severe (consider transfusion in symptomatic patients). Causes: iron deficiency (commonest in India), B-12 / folate deficiency, chronic disease, recent bleeding, haemoglobinopathies (thalassemia, sickle cell), kidney disease, haemolysis. Always investigate the cause — never just treat with iron alone. | > 17 in men, > 15 in women = polycythaemia. Causes: dehydration (most common), smoking, chronic lung disease, sleep apnoea, living at altitude, rarely primary polycythaemia vera (a bone-marrow disorder). Persistent unexplained elevation needs haematology workup. |
Anemia severity by haemoglobin (WHO 2024)
| Group | No anemia | Mild | Moderate | Severe |
|---|---|---|---|---|
| Non-pregnant women (15+ yrs) | ≥ 12.0 g/dL | 11.0–11.9 | 8.0–10.9 | < 8.0 |
| Pregnant women | ≥ 11.0 g/dL | 10.0–10.9 | 7.0–9.9 | < 7.0 |
| Men (15+ yrs) | ≥ 13.0 g/dL | 11.0–12.9 | 8.0–10.9 | < 8.0 |
| Children 5–11 yrs | ≥ 11.5 g/dL | 11.0–11.4 | 8.0–10.9 | < 8.0 |
| Children 12–14 yrs | ≥ 12.0 g/dL | 11.0–11.9 | 8.0–10.9 | < 8.0 |
Frequently asked questions
Do I need to fast for a Hemoglobin test?
No. Haemoglobin can be measured at any time of day with no fasting required.
My haemoglobin is 10 — is that dangerous?
A haemoglobin of 10 g/dL is moderate anemia in a non-pregnant adult. Most people at this level have noticeable symptoms (fatigue, breathlessness on exertion, palpitations). See your doctor — finding the cause is more important than just starting iron tablets, because the right treatment depends on whether the cause is iron deficiency, B-12 deficiency, chronic disease, blood loss or a haemoglobin disorder.
How is haemoglobin different from a CBC?
A CBC includes haemoglobin plus many other parameters (RBC count, WBC, platelets, MCV, MCH, MCHC, RDW, differential count). Standalone haemoglobin is cheaper and faster if all you need is an anemia check; CBC is the standard if you want the full blood picture.
Can I improve haemoglobin with diet alone?
Mild iron-deficiency anemia often improves with iron-rich foods (leafy greens, jaggery, dates, lentils, eggs, meat / fish) and vitamin C to enhance absorption (citrus, amla, guava). Avoid drinking tea / coffee with meals — tannins block iron absorption. Moderate-to-severe deficiency usually needs oral iron supplements; very severe cases need IV iron or transfusion.
Why is anemia so common in Indian women?
Multiple reasons compound: low dietary iron (mostly vegetarian), low bioavailability (high tannin / phytate intake), monthly menstrual losses, repeated pregnancies, and limited access to screening. National policy (anemia mukt bharat) addresses this with weekly iron-folic acid supplementation, but household awareness and adherence remain limited.
How often should I check haemoglobin?
Annually for all adults; every trimester in pregnancy; every 3 months in adolescent girls and women of reproductive age on iron supplementation; more often if you have known chronic disease, kidney disease, or active treatment for anemia.
I am pregnant — what is the minimum acceptable haemoglobin?
WHO defines anemia in pregnancy as haemoglobin below 11.0 g/dL. Indian antenatal protocols treat mild anemia (10–10.9) with oral iron-folic acid; moderate (7–9.9) with higher-dose oral iron or IV iron; severe (<7) with IV iron and consideration of transfusion. Adequate haemoglobin reduces the risk of low birth weight, prematurity and maternal complications.
My haemoglobin is high — should I worry?
Mild elevation (men >17, women >15) is most often dehydration or smoking. Persistent elevation despite hydration needs investigation — chronic lung disease, sleep apnoea, high altitude, or rarely polycythaemia vera (a bone-marrow disorder needing haematology care).
Related Hematology / Anemia tests
Tests commonly ordered alongside HEMOGLOBIN, or that help interpret an unexpected result.
Sources & references
- WHO — Haemoglobin concentrations for the diagnosis of anaemia (2024) · accessed 2026-05-29T00:00:00.000Z
- NIH MedlinePlus — Hemoglobin Test · accessed 2026-05-29T00:00:00.000Z
- National Family Health Survey (NFHS-5) — Anaemia in India · accessed 2026-05-29T00:00:00.000Z
- NCBI StatPearls — Hemoglobin · accessed 2026-05-29T00:00:00.000Z
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