Image: A laboratory technician holding a blood sample tube for analysis. The MCHC blood test (Mean Corpuscular Hemoglobin Concentration) is part of a routine complete blood count (CBC) that measures the average concentration of hemoglobin in your red blood cells. This value reflects how densely your red blood cells are packed with hemoglobin, the protein that carries oxygen. A typical MCHC blood test normal range is about 32–36 g/dL (34 ± 2 g/dL). Values outside this range may signal health issues. By understanding the MCHC blood test meaning, you can learn what a low or high result might imply for your health and why your doctor ordered this test.
Understanding MCHC: What It Means and Its Purpose
MCHC stands for Mean Corpuscular Hemoglobin Concentration. In simple terms, it tells how much hemoglobin is present in a given volume of red blood cells. It is calculated by dividing the hemoglobin level by the hematocrit (the percentage of blood made up of red cells). In practice, most modern labs calculate MCHC automatically when they perform a CBC. The MCHC blood test purpose is to help diagnose and classify different types of anemia and other blood disorders. Because it accounts for both hemoglobin and cell size, the MCHC can indicate whether red cells are abnormally packed with hemoglobin or unusually sparse (hypochromic). Doctors use it along with other red blood cell indices (like MCV and MCH) to pinpoint underlying causes of anemia.
MCHC is expressed in grams per deciliter (g/dL) or as a percentage. Normal adults usually have an MCHC around 34 g/dL. An MCHC blood test result below about 32 g/dL is considered low, while values above 36 g/dL are high. These cutoffs can vary slightly by lab. By itself, an abnormal MCHC doesn’t confirm a diagnosis, but it “reveals” patterns – for example, low MCHC means red cells carry less hemoglobin (hypochromia), whereas high MCHC means red cells carry more concentrated hemoglobin or are abnormally shaped.
MCHC Blood Test Normal Range
Understanding the MCHC blood test normal range is key. For most adults, normal MCHC is roughly 32–36 g/dL. One authoritative source notes “the normal values for MCHC are 34 ± 2 g/dL”. In clinical practice, if your lab report shows an MCHC in this range, that aspect of your blood count is considered normal. Slight deviations might occur due to hydration status or lab differences, but values well outside 32–36 g/dL warrant attention.
If your MCHC blood test results fall outside the normal range, your healthcare provider will interpret them in context of other findings. A result below 32 g/dL (low MCHC) suggests hypochromic anemia – red cells with less hemoglobin than normal. A result above 36 g/dL (high MCHC) suggests hyperchromic cells, often seen in conditions where cells are small or dehydrated (see below). The lab report often marks “H” for high or “L” for low next to the MCHC value. Remember, one abnormal value usually leads to more testing (like iron studies or a blood smear) to find the cause.
Low MCHC: Causes and Symptoms
When your MCHC blood test is low, it usually indicates hypochromic anemia – your red blood cells have less hemoglobin than they should. The most common cause is iron deficiency. Without enough iron, the body can’t make sufficient hemoglobin, so red cells become paler (less hemoglobin) and often smaller. Chronic blood loss (from heavy periods, ulcers, or internal bleeding) can also deplete iron stores, leading to low MCHC. Other causes include chronic diseases (like long-standing kidney or inflammatory conditions) and inherited disorders (such as thalassemia).
Common causes of low MCHC include:
- Iron deficiency anemia – lack of dietary iron or absorption problems.
- Chronic bleeding – heavy menstruation or slow internal bleeding (e.g. ulcers).
- Malabsorption – conditions like celiac disease or inflammatory bowel disease prevent iron uptake.
- Hemolytic anemia – excess destruction of red cells can eventually lower MCHC.
Patients with low MCHC often have symptoms of anemia. Because hemoglobin carries oxygen, a deficit causes fatigue and weakness. Typical symptoms of low MCHC mirror iron-deficiency anemia:
- Fatigue or chronic tiredness
- Shortness of breath on exertion
- Pale or sallow skin
- Dizziness or lightheadedness
- Cold hands/feet, rapid heartbeat (palpitations)
Tip: If your MCHC is low, your doctor will likely order iron studies (serum iron, ferritin) and other blood tests to confirm iron deficiency or find other causes.
High MCHC: Causes and Symptoms
A high MCHC result is less common. It means red blood cells are unusually rich in hemoglobin or abnormally shaped, so the average concentration is above normal. Conditions that can raise MCHC include:
- Hereditary spherocytosis – a genetic disorder causing spherical (not biconcave) red cells that concentrate hemoglobin.
- Autoimmune hemolytic anemia – rapid breakdown of red cells can leave behind smaller, more hemoglobin-dense cells.
- Liver disease – chronic liver problems can alter blood composition, sometimes increasing MCHC.
- Hyperthyroidism – an overactive thyroid may raise MCHC in some cases.
- Severe burns or dehydration – fluid loss shrinks plasma volume, concentrating red cells and raising MCHC.
Rarely, spurious factors can cause a falsely high MCHC. For example, very lipemic (fatty) blood or sample hemolysis can artifactually inflate the hemoglobin reading. Automated analyzers also occasionally report a high MCHC if red cells clump.
Symptoms associated with high MCHC depend on the underlying cause. For example, autoimmune hemolytic anemia (which raises MCHC) often causes fatigue, jaundice (yellow skin/eyes), spleen enlargement and paleness. Hereditary spherocytosis may cause anemia symptoms, jaundice, and gallstones. In general, the symptoms (if any) mirror the condition: high MCHC itself doesn’t cause symptoms, but conditions like hemolytic anemia do.
Important: A single high MCHC result usually prompts checking for hemolysis markers, looking at a blood smear, or reviewing the sample (e.g. for cold agglutinins). Always follow up with your doctor for interpretation.
Interpreting MCHC Blood Test Results
Your doctor interprets the MCHC blood test results along with other CBC values. MCHC by itself is one piece of the puzzle. For instance, low MCHC with low MCV (mean cell volume) typically points to iron deficiency or thalassemia. Low MCHC with normal MCV might suggest mild iron deficiency or anemia of chronic disease. High MCHC often correlates with hyperchromic anemias; if MCV is low or normal, consider spherocytosis or artifacts; if MCV is high, consider vitamin deficiency or reticulocytosis.
In practical terms:
- If MCHC is low, doctors suspect hypochromic anemia. They will check iron levels, ferritin, and possibly gastrointestinal bleeding.
- If MCHC is high, they consider hyperchromic causes. A blood smear might show spherocytes (suggesting spherocytosis) or agglutination. Other causes like hyperthyroidism or liver tests might be checked.
Keep in mind that MCHC is calculated, not directly measured. Extremely high values may indicate a lab artifact. For example, cold agglutinins (clumping of RBCs) or sample interference can falsely elevate MCHC. If results are confusing, repeating the test or doing complementary tests (like measuring CHCM on special analyzers) helps.
MCHC Blood Test Purpose and When It’s Done
The purpose of the MCHC blood test is to help diagnose and classify anemias and other blood disorders. It’s not a standalone test – MCHC is one of several RBC indices reported with a CBC. Doctors order it routinely in a CBC when checking for anemia, fatigue, or any condition that might affect blood counts. For example:
- Routine health exams often include CBC (and thus MCHC) to screen for early anemia.
- Unexplained fatigue, weakness or pale skin lead to CBC ordering.
- Follow-up on known anemia or chronic disease uses repeated MCHC measurements to track progress.
There is no special preparation for an MCHC test; it requires only a standard blood draw. The test is quick and is processed with your other CBC values. Because MCHC can suggest specific causes of anemia, it helps doctors decide what additional tests are needed (iron studies, vitamin levels, genetic tests, etc.).
Frequently Asked Questions (FAQs)
Q: What is the MCHC blood test and why is it done?
A: The MCHC blood test measures the average concentration of hemoglobin in a given volume of your red blood cells. It’s part of a complete blood count (CBC) and is done to help identify types of anemia or red blood cell disorders.
Q: What is the normal range for MCHC?
A: Normal MCHC is roughly 32–36 g/dL in adults. Your lab report should list a reference range. Values below ~32 are considered low, and above ~36 high.
Q: What does it mean if my MCHC blood test is low?
A: A low MCHC (below ~32 g/dL) means your red blood cells have less hemoglobin than usual (they are hypochromic). This often indicates iron deficiency anemia or similar conditions. You might have symptoms like fatigue or pale skin.
Q: What does a high MCHC indicate?
A: A high MCHC (above ~36 g/dL) is less common. It can occur in conditions where red cells are unusually concentrated with hemoglobin, such as hereditary spherocytosis or autoimmune hemolytic anemia. Lab factors (like lipemia) can also falsely raise MCHC.
Q: How should I interpret my MCHC results?
A: MCHC must be interpreted with other CBC values. A doctor will look at your hemoglobin, hematocrit, MCV (cell size) and other indices to determine the cause. For example, low MCHC and low MCV often mean iron-deficiency anemia. A hematologist or your physician will explain what your specific results suggest.
Q: Are there any symptoms specific to abnormal MCHC?
A: MCHC itself doesn’t cause symptoms; symptoms come from underlying conditions. Low MCHC (anemia) causes fatigue, weakness, and pale skin. High MCHC conditions like hemolytic anemia may cause jaundice (yellowing), rapid heartbeat, or spleen enlargement.
Q: What should I do if my MCHC is abnormal?
A: Consult your doctor. They may order follow-up tests (iron studies, vitamin levels, a blood smear, etc.) and discuss your symptoms. Treatment depends on the cause (e.g., iron supplements for iron-deficiency anemia).
Understanding your MCHC blood test results can provide important clues about your blood health. Always review your results with a healthcare professional. If you found this information helpful, consider sharing it. Your questions and comments are welcome below!
