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MCHC blood tests measure the haemoglobin concentration in red blood cells relative to their size. High or low MCHC levels can signify anaemia.
Written by Leanne Edermaniger
June 20, 2024
Reviewed by:
Dr Thom PhillipsMean cell haemoglobin concentration (MCHC) is the average haemoglobin concentration in a specific volume of red blood cells.
Haemoglobin is the iron-rich protein responsible for transporting oxygen around the body. An MCHC blood test is usually taken as part of a full blood count and used as a preliminary test for anaemia and other red cell disorders, such as thalassaemia.
An MCHC blood test can also help diagnose conditions that affect the size of red blood cells[1].
A mean cell haemoglobin concentration or MCHC blood test is taken as part of a full blood count, and the reference range should be between 310 and 350 g/L[2].
High MCHC levels above 350 g/L indicate a high haemoglobin concentration in the blood.
Low levels are diagnosed when the MCHC level is below 310 g/L and are linked to iron deficiency anaemia and thalassaemia.
A high MCHC blood test result is received when a person has a high haemoglobin concentration in their red blood cells, but it can also occur when red cells are weak or broken, causing haemoglobin to be present outside of the red cells.
High MCHC levels can be caused by:
Autoimmune haemolytic anaemia is a rare disease where antibodies increasingly break down red blood cells. Over half of people who develop the disease have an underlying condition[3].
Symptoms of autoimmune haemolytic anaemia include:
Hereditary spherocytosis is the most common inherited haemolytic condition, affecting approximately 1 in 2000 people. The condition causes a genetic mutation which affects the red cell membrane structure, causing it to become fragile and at greater risk of destruction[5].
The symptoms of hereditary spherocytosis are:
In some extreme burn cases, MCHC levels can be high, particularly if more than 10% of the body has been affected. That’s because severe burns can cause haemolytic anaemia and the person may require blood transfusions to treat it.
An overactive thyroid or hyperthyroidism may cause changes in red blood cells, including a high MCHC value[6].
If your MCHC level is high, you have a higher concentration of haemoglobin in your blood which could suggest an autoimmune or inherited condition. If your MCHC levels are outside of normal parameters, you should contact your GP for advice.
The most common cause of a low mean corpuscular haemoglobin concentration is anaemia.
Anaemia causes the number of red blood cells or haemoglobin levels to be lower than they should be. Haemoglobin is important for carrying oxygen around the body to the tissues. If it is low, its ability to bind to oxygen is reduced, causing symptoms like fatigue, weakness, and shortness of breath.
There are several types and causes of anaemia, including nutritional deficiencies. Microcytic anaemia is commonly associated with low MCHC and is caused by iron deficiency and thalassaemia[7].
A low MCHC can indicate iron deficiency anaemia and is caused by a lack of iron in the diet or issues with iron absorption. Several chronic diseases including kidney disease, heart failure, and cancer can also cause it[8].
Thalassaemia is an inherited blood condition which impacts the body’s ability to produce normal haemoglobin. Because the symptoms can be similar, thalassaemia can be misdiagnosed as iron deficiency anaemia[9].
Thalassaemia affects the synthesis of globin chains leading to disrupted red blood cell production (erythropoiesis), increased breakdown of red blood cells, and disturbed iron homeostasis[10].
The symptoms of a low MCHC are similar to those associated with iron deficiency anaemia, like:
The best way to keep MCHC levels within a normal range is to prevent the occurrence of iron deficiency anaemia by incorporating a good amount of iron into your diet.
There are two types of iron available; haem and non-haem. Haem iron is better absorbed than non-haem iron, accounting for 10 to 15% of total iron intake, but because of the greater absorption, it’s likely to account for more than 40% of the total absorbed iron.
Haem iron sources | Non-haem iron sources |
Liver | Green leafy vegetables (spinach, kale) |
Red meat (beef, lamb) | Beans (edamame beans, chickpeas, red kidney beans) |
Shellfish (oysters, clams, mussels) | Fortified cereals |
Poultry (chicken, turkey) | Nuts |
Tinned sardines | Lentils |
Canned tuna | Dark chocolate |
Anyone who follows a vegan or vegetarian diet is at a greater risk of iron deficiency because they will need to get their iron from plant-based sources which tend to be less well absorbed. However, the absorption of non-haem iron tends to be improved in the presence of vitamin C, such as orange or lemon juice. Tea, on the other hand, can block iron absorption, so this is best avoided around meal times.
Dehydration can cause a high mean corpuscular haemoglobin concentration, so it’s important to keep your fluid levels topped up throughout the day. Dehydration causes blood plasma volume to reduce because water will be distributed around the body to the cells and tissues that need it most.
One of the earliest signs of dehydration is thirst which can be avoided by drinking small amounts of water regularly throughout the day. The UK Government advises we should all aim to drink 6 to 8 glasses or 1.2 litres of water or fluid per day[11].
Based in the UK, Leanne specialises in writing about health, medicine, nutrition, and fitness.
She has over 5 years of experience in writing about health and lifestyle and has a BSc (hons) Biomedical Science and an MSc Science, Communication and Society.
Zeerleder, S., 2011. Autoimmune haemolytic anaemia-a practical guide to cope with a diagnostic and therapeutic challenge. Neth J Med, 69(4), pp.177-84.
Dorgalaleh, A., Mahmoodi, M., Varmaghani, B., Kiani Node, F., Saeeidi Kia, O., Alizadeh, S.h, Tabibian, S.h, Bamedi, T., Momeni, M., Abbasian, S., & Kashani Khatib, Z. (2013). Effect of thyroid dysfunctions on blood cell count and red blood cell indice. Iranian journal of pediatric hematology and oncology, 3(2), 73–77.
Urrechaga, E. et al. (2014) ‘Differential diagnosis of microcytic anemia: The role of microcytic and hypochromic erythrocytes’, International Journal of Laboratory Hematology, 37(3), pp. 334–340. doi:10.1111/ijlh.12290.
Lopez, A., Cacoub, P., Macdougall, I.C. and Peyrin-Biroulet, L., 2016. Iron deficiency anaemia. The Lancet, 387(10021), pp.907-916.
Thom works in NHS general practice and has a decade of experience working in both male and female elite sport. He has a background in exercise physiology and has published research into fatigue biomarkers.
Dr Thom Phillips
Head of Clinical Services
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