Key takeaways
- MCHC (mean corpuscular haemoglobin concentration) shows how concentrated the haemoglobin is inside your red blood cells, and it is reported on every full blood count.
- MCHC is calculated from your haemoglobin and haematocrit, or equivalently from MCH relative to MCV, so it always sits alongside those other two red cell measurements.
- A low MCHC is most often linked to iron deficiency, while a high MCHC is more often a sign of how the sample behaved in the laboratory than a true change in your red cells.
- At Blood London a full blood count costs £63.75 plus the £50 blood draw, with results in 1 day by email.
- Your report shows the laboratory's reference range next to each result, so whether your MCHC counts as high or low depends on that range rather than a single number everyone shares.
- If your MCHC is flagged, targeted follow-up tests such as an iron status profile or a ferritin test can help find out why.
MCHC (mean corpuscular haemoglobin concentration) is the average concentration of haemoglobin inside your red blood cells, shown on every full blood count (FBC). On its own it rarely changes a diagnosis: it is read alongside your haemoglobin, MCV and MCH. If your MCHC has been flagged, a full blood count is a sensible starting point for a wider look at your blood picture.
Book a full blood count at 117a Harley Street: £63.75 plus the £50 blood draw, results in 1 day.
What does MCHC actually measure?
MCHC measures how much haemoglobin is packed into a given volume of your red blood cells, expressed as a concentration rather than an amount. Haemoglobin is the protein in red blood cells that carries oxygen, so MCHC is really asking: for the amount of red cell you have, how much haemoglobin is inside it. It is calculated from your haemoglobin and haematocrit results, or equivalently worked out from MCH relative to MCV, so a laboratory doesn't measure MCHC directly with its own separate test; it derives it from other full blood count values.
MCHC vs MCH vs MCV: what's the difference?
MCV, MCH and MCHC all describe your red blood cells, but each looks at a different property.
| Marker | What it measures |
|---|---|
| MCV (mean corpuscular volume) | The average size of your red blood cells |
| MCH (mean corpuscular haemoglobin) | The average amount of haemoglobin inside a single red blood cell |
| MCHC (mean corpuscular haemoglobin concentration) | How concentrated that haemoglobin is within the cell, taking the cell's size into account |
Because these three markers are related, a clinician usually looks at them together rather than at MCHC alone. A low MCV and low MCH often appear alongside a low MCHC, for example, which points more clearly towards a particular pattern than any one marker on its own.
What can a low MCHC mean?
A low MCHC most often points to iron deficiency, since haemoglobin production depends on having enough iron available. When there isn't enough iron, red blood cells can end up with less haemoglobin packed into them, which shows up as a lower MCHC alongside a low MCH and often a low MCV. Less often, an inherited condition such as thalassaemia trait produces a similar pattern. A low MCHC on its own, without other abnormal red cell markers, is not always significant, and your clinician is best placed to say whether it needs following up with further tests.
What can a high MCHC mean?
A high MCHC is less common, and it is more often related to how the sample behaved during processing than to a genuine change in your red cells. Factors that can interfere with the blood sample itself, such as high levels of certain proteins or fats in the blood, can push the measured MCHC upward without your red cells actually carrying more haemoglobin. Less often, a genuinely high MCHC is seen in conditions where red cells are an unusual shape, such as hereditary spherocytosis, or where red cells are breaking down faster than usual. Because of this, a raised MCHC is often repeated to confirm whether it is a true finding, and any unexpected result should be discussed with a clinician rather than interpreted alone.
What to test next if your MCHC is abnormal
If your MCHC is outside the laboratory's reference range, the next step usually depends on what else is unusual on your full blood count and how you feel. An anaemia blood test profile checks your red cells together with the iron, folate and vitamin B12 needed to make them, which is useful when a low MCHC appears alongside low haemoglobin (£226.25 plus the £50 blood draw, results in 2 days). An iron status profile looks specifically at how much iron is in your blood, how much is stored, and how well it is being carried (£126.25 plus the £50 blood draw, results in 1 day). A standalone ferritin blood test checks how much iron you have stored, which is often the first thing a clinician wants to see if iron deficiency is suspected (£68.75 plus the £50 blood draw, results in 1 day).
Getting a full blood count on Harley Street
A full blood count at Blood London costs £63.75 plus the £50 blood draw, with results usually available in 1 day by email. No fasting or special preparation is needed beforehand. Like all our private blood tests in London, you can self-request it without a GP referral, book online or walk in to 117a Harley Street seven days a week.
Book your full blood count online, or walk in seven days a week at 117a Harley Street: £63.75 plus the £50 blood draw. Start your booking.
Frequently asked questions
What is a normal MCHC range?
Your report shows the laboratory's own reference range next to your MCHC result, and what counts as normal depends on that range. If your result sits outside it, ask your clinician to talk you through what that means for you.
Is a slightly low MCHC something to worry about?
Not necessarily. A slightly low MCHC on its own, without other abnormal red cell markers, is often not significant, but your clinician is best placed to decide whether it needs any follow-up.
Can dehydration change MCHC?
Not usually. Dehydration can raise haemoglobin and haematocrit, but because MCHC compares the two, it is not normally changed by dehydration.
Do I need to fast for a full blood count?
No. There is no fasting or other preparation needed for a full blood count, so you can eat and drink normally beforehand.
How quickly will I get my full blood count results?
Results are usually available in 1 day and are sent to you by email.
Will a doctor explain my results?
Yes, if you add a doctor review to your test, which costs £75 at Blood London. For a full consultation about an abnormal result, you can book a private GP consultation at Medical Express Clinic, which costs £150.
References
- NHS: Blood tests
- Lab Tests Online UK: Full blood count (FBC)
- NICE Clinical Knowledge Summaries: Anaemia, iron deficiency
- NHS: Iron deficiency anaemia