Mean corpuscular haemoglobin: average haemoglobin per red cell.
What it is
MCH is reported in picograms (pg) and usually moves in the same direction as MCV in iron deficiency or macrocytosis.
Mean corpuscular haemoglobin (MCH) is the average mass of haemoglobin per red cell, in picograms. Automated counters derive it from haemoglobin and RBC count. It usually tracks MCV: smaller iron-deficient cells carry less haemoglobin.
Why it matters
Low MCH often tracks with iron deficiency or thalassaemia trait, mirroring a low MCV. High MCH usually accompanies macrocytosis from B12/folate issues, alcohol, liver disease, or medicines.
Use MCH with MCV, MCHC, haemoglobin, and ferritin, never as a single decision point. If you feel tired with a suggestive pattern, ask a clinician about iron studies or vitamin levels rather than self-supplementing.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
MCH reflects how much haemoglobin was packed into each red cell during marrow maturation. When iron is scarce, cells carry less haemoglobin; when DNA synthesis is impaired, larger cells may carry more absolute haemoglobin even while oxygen delivery overall is poor if anaemia is present.
For athletes
For athletes monitoring iron status, MCH is corroborative: falling MCH with falling ferritin and haemoglobin strengthens the iron story. It is not a training load metric. Recheck after a consistent fueling block rather than after a single race week.
