Mean Corpuscular Haemoglobin

Mean corpuscular haemoglobin tells you the average amount of haemoglobin contained within each of your red blood cells, measured in picograms. It answers the question: how much oxygen-carrying protein is each cell loaded with? This marker matters because haemoglobin is the molecule responsible for picking up oxygen in your lungs and delivering it throughout your body. If each red blood cell is carrying a healthy amount, your tissues receive a reliable supply of oxygen to power everything from muscle movement to mental focus. When the average load per cell drops, you may gradually notice symptoms like tiredness or reduced stamina, even if your overall red blood cell count appears normal.

Think of your red blood cells as small delivery trucks and haemoglobin as the parcels they carry. MCH tells you how many parcels, on average, each truck has on board. A truck that sets off half empty is still making the journey, but it is not delivering as much as it could in each trip. Your body relies on having well loaded cells to meet its oxygen demands efficiently, particularly during exercise or periods of physical stress. The production of haemoglobin depends heavily on a steady supply of iron, along with supporting nutrients like vitamin B12 and folate.

When iron is running low, whether through blood loss, diet, absorption difficulties, or increased demand, the amount of haemoglobin packed into each cell can fall. Conversely, certain vitamin deficiencies can cause cells to grow larger and carry more haemoglobin per cell, which can also signal an imbalance. If your MCH is outside the expected range, it is worth raising with your GP, who can consider it alongside your other blood markers and advise on whether a dietary review, further testing, or supplementation might be beneficial.