Mean Corpuscular Haemoglobin Concentration (MCHC)
MCHC is a measure of how densely haemoglobin — the part that carries oxygen — is packed inside your red blood cells, a bit like how full each cell is. It is one of a few red cell measures on a full blood count. Your GP reads it together with the size of your cells and the rest of your count to help understand the type and possible cause of anaemia.
Standard CareWhat is mean corpuscular haemoglobin concentration (mchc)?
MCHC stands for Mean Corpuscular Haemoglobin Concentration. Where MCH tells you the total amount of haemoglobin in a single red cell, MCHC tells you how concentrated that haemoglobin is — that is, how densely it is packed relative to the cell's volume. Haemoglobin is the iron-rich protein that carries oxygen from your lungs to every tissue in your body. Red blood cells are essentially tiny sacks of haemoglobin; MCHC describes how full those sacks are. MCHC is calculated from other values in your full blood count (FBC) and is expressed in grams per litre (g/L). It is always interpreted as part of a group of red cell indices — alongside MCV (mean cell volume, the average size of red cells) and MCH (mean cell haemoglobin, the average amount of haemoglobin per cell). On its own, MCHC is a supporting number; in combination, these indices help your GP identify the pattern of anaemia and narrow down the cause.
Why is it tested?
MCHC is measured because it adds detail to a low haemoglobin result. Knowing that haemoglobin is low is a starting point — knowing whether red cells are pale and lightly loaded (low MCHC) or normally loaded (normal MCHC) helps point toward a cause. Red cell indices including MCHC are used to investigate anaemia and vitamin deficiencies, bone marrow disorders, and liver disease. They help classify anaemia so that further testing can be targeted. MCHC is not usually requested on its own — it appears automatically as part of every standard full blood count. If your GP orders an FBC to investigate fatigue, breathlessness, pale skin, or a known condition such as iron deficiency, MCHC will be on the results page.
Reference range (Australia)
Reference intervals for MCHC are laboratory- and analyser-specific. Different analysers and reagent sets produce slightly different intervals, so the range printed on your pathology report is the correct one to use for your result. Do not compare your result against a number found online.
Reference intervals vary between laboratories. Always use the range printed on your own report.
What your result means
A low MCHC means red blood cells contain a lower concentration of haemoglobin than expected — often described as hypochromic (hypo = under, chrom = colour) because they appear pale under a microscope. The most common cause is iron deficiency anaemia, where insufficient iron means less haemoglobin can be made. Thalassaemia, an inherited condition affecting haemoglobin production, can produce a similar pattern. A low MCHC alone does not confirm a diagnosis. Your GP will look at it alongside MCV, haemoglobin, ferritin, and iron studies to work out the likely cause and whether further investigation is needed.
An MCHC within the range on your report suggests red cell haemoglobin concentration is adequate. If haemoglobin is also normal, that is reassuring. If haemoglobin is low but MCHC is normal, your GP will look at cell size (MCV) and other indices to understand why — for example, vitamin B12 or folate deficiency tends to produce large, normally loaded cells rather than pale ones. A normal MCHC does not rule out anaemia; it helps characterise its pattern.
A slightly elevated MCHC can appear when red cells are abnormally fragile and bursting (haemolytic anaemia), in certain inherited conditions, or sometimes as a laboratory artefact. Marked elevation is uncommon. A mildly high MCHC on a single result is often not clinically significant on its own. Your GP will look at the full picture — other red cell indices, haemoglobin, and your symptoms — before drawing any conclusions. It is worth mentioning at your next appointment so they can review it in context.
What can affect your result
Iron availability has the biggest influence on MCHC. Iron is central to the haemoglobin molecule; without enough iron, red cells are produced with less haemoglobin inside them, lowering MCHC. Ferritin (your iron-storage protein) and iron studies are the tests that pin this down further. Vitamin B12 and folate deficiency tend to produce large red cells with a normal MCHC — so these deficiencies affect cell size (MCV) more than concentration. To make red blood cells at all, your body needs nutrients such as vitamin B12, folate, and iron. Certain inherited conditions affecting haemoglobin structure or production — including thalassaemia — can lower MCHC independently of iron status. Hydration can affect the calculated result. Severe dehydration concentrates the blood, potentially nudging the reading. Some medications and chronic conditions affect red cell production indirectly — your GP will weigh these up when interpreting the result alongside haemoglobin and other indices.
When to act
MCHC is a supporting index rather than a standalone test. If your MCHC is outside the range on your report, the most useful step is to look at it alongside haemoglobin, MCV, MCH, ferritin, and iron studies — which is exactly what your GP will do. If haemoglobin is also low, speak with your GP so they can put the pattern together, consider your symptoms and history, and decide whether further testing is warranted. If MCHC is outside range but haemoglobin is normal and you have no symptoms, it is still worth mentioning at your next visit — your GP can tell you whether it needs monitoring or a follow-up count. This page is general information and is not a substitute for advice from your GP.
Frequently asked questions
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