Low or High MCV? What Your Blood Test Says About Your Health

Blood tests are a key determinant of overall health. Many people undergo blood tests as part of routine health check-ups, while others do so when they have health concerns. There are different types of blood tests, each measuring different components, including cells, minerals, electrolytes, and proteins. MCV is a CBC parameter that measures the average size of red blood cells and helps narrow the causes of anaemia. It supports the diagnosis of conditions that include types of anaemia, when interpreted alongside other CBC results and your symptoms. Getting a report of high or low MCV can tell a lot about what’s happening inside your body. In this blog, we will discuss what MCV means, its normal range, the causes and symptoms of high and low MCV, and what to do in case of high and low MCV, to help you take better control of your health. 

What is MCV in a Blood Test?

MCV stands for Mean Corpuscular Volume, in a blood test. It measures the average size of red blood cells and helps determine whether they are large enough to carry oxygen effectively throughout the body. In a complete blood count test, the MCV is automatically included as part of the standard panel. 

What does MCV mean in a blood test? 

In a blood test, MCV signify the size of red blood cells. The cell size can be: 

1. Smaller than normal (Microcytic)

2. Normal size (Normocytic)

3. Larger than normal (Macrocytic)

Recognising the size of red blood cells is essential to understand potential causes behind symptoms like fatigue, weakness, or shortness of breath. The cell sizes can also point toward specific nutritional deficiencies, chronic diseases, or other health conditions that might need attention.

Understanding the MCV Blood Test Range

The MCV blood test range, measured in femtolitres (fL), can vary from normal to low or high depending on a patient’s age, gender, and overall health status. Understanding these ranges is essential for identifying potential health issues early and gaining a clear picture of what’s happening inside the body.

MCV Blood Test Normal Range

In a blood test, the normal range for MCV is between 80-100 fL. This range signifies that the red blood cells are proportionate to the amount of oxygen that needs to be transported in the body.

A normal range for the RBC count suggests the following:

• The body possesses an adequate amount of iron.

• Levels of vitamin B12 and folate are within an acceptable range.

• The bone marrow is healthy and is producing ample red blood cells that are properly nourished and adequately developed.

• There are no clinically significant blood disorders present.

Caution: Normal MCV range alone does not mean there is no illness. Some illnesses can coexist alongside a normal red blood cell size. For these situations, other blood markers should be checked alongside MCV for the most dependable and accurate results.

What If MCV Is Low in a Blood Test?

Low MCV (below 80 fL), identified by small-sized red blood cells, signals that your body is not getting enough nutrients to produce healthy red blood cells that are capable of carrying the required oxygen to the body. This condition is called microcytic anaemia. Mainly, low MCV is caused by iron deficiency, but other factors can also contribute to the condition. The symptoms develop gradually, and as the condition progresses, fatigue and tiredness become common. If you or a loved one is experiencing any signs, book a simple MCV blood test at-home and get clarity on the matter before it becomes worse. 

What If MCV Is High in a Blood Test?

High MCV (above 100 fL) is identified by the presence of red blood cells that are larger than the normal size. This condition, called macrocytic anaemia, is a signal that the body is lacking certain vitamins and folic acid that are required for healthy red blood cell formation. In this condition, movement of red blood cells through tiny vessels becomes restricted, potentially impacting oxygen supply to the body. The cautionary aspect of a high MCV is that it can appear in your blood test results much earlier than any symptoms, making the MCV blood test crucial.

Causes and Symptoms of Abnormal MCV

Abnormal (high or low) MCV levels develop over time due to various factors, and knowing the reasons can help prevent various health issues.

Low MCV: Causes and Symptoms

The main cause of Low MCV is iron deficiency; however, there are several other factors as well, causing low MCV in blood test: 

Primary causes of low MCV include:

1. Iron deficiency from poor diet, blood loss, or absorption problems

2. Chronic disease anaemia, which is associated with long-term illness

3. Thalassaemia, a genetic blood disorder

4. Lead poisoning, a rare but serious cause 

5. Sideroblastic anaemia, also known as, bone marrow disorder

Symptoms of Low MCV develop gradually as the condition progresses. One can experience: 

• Persistent fatigue that doesn't improve with rest

• Pale skin, nail beds, or inner eyelids

• Shortness of breath during normal activities

• Cold hands and feet

• Brittle or spoon-shaped fingernails

• Unusual cravings for ice, starch, or non-food items

• Difficulty concentrating or remembering things

Iron deficiency affects millions worldwide, including women of childbearing age, who are particularly susceptible to iron deficiency due to monthly blood loss. In the same way, vegetarians and vegans may struggle to get enough absorbable iron from their diet alone.

High MCV: Causes and Symptoms

The common causes of High MCV in a blood test are vitamin B12 or folate deficiency, though several other conditions can also cause red blood cells to grow larger than normal.

Common causes of elevated MCV are:

1. Vitamin B12 deficiency from poor absorption or inadequate intake

2. Folate deficiency, often linked to diet or certain medications

3. Excessive alcohol consumption, which in turn affects vitamin absorption

4. Liver disease, impacting vitamin storage and metabolism

5. Thyroid disorders influencing cellular metabolism

6. Certain medications like metformin or anti-seizure drugs

Symptoms of high MCV may develop much later because of the condition’s complications. However, it generally includes:

• Weakness and fatigue that gradually worsen

• Tingling or numbness in the hands and feet

• Difficulty walking or balancing problems

• Memory issues or confusion

• Pale or yellowish skin tone

• Smooth, red tongue

• Mood changes or depression

• Heart palpitations or rapid heartbeat

B12 deficiency can be particularly tricky because symptoms develop very slowly, sometimes over months or years. This gradual onset means people often dismiss early warning signs as normal ageing or stress.

What to Do If Your MCV Is Too Low or Too High

Noticed any symptoms of abnormal MCV levels? A simple and convenient MCV blood test at home can help you determine whether your RBCs are small or large. In any case, proper medical guidance can help get the MCV back to normal. The exact step you need to take will depend on whether your MCV is high or low. Common actions you can take in case of high and low MCV are suggested below. 

What to Do If You Have Low MCV Levels:

• Increase iron-rich foods like lean meats, spinach, lentils, and fortified cereals

• Combine iron sources with vitamin C from citrus fruits or tomatoes to boost absorption

• Avoid tea and coffee with iron-rich meals as they can block absorption

• Consider iron supplements if recommended by your healthcare provider

• Address underlying blood loss through medical evaluation

What to Do If You Have High MCV Levels: 

• Add B12-rich foods such as fish, meat, eggs, and dairy products

• Include folate sources like leafy greens, beans, and fortified grains

• Limit alcohol consumption to support better vitamin absorption

• Review current medications with your doctor for potential interactions

• Consider vitamin supplements under medical supervision

When to seek immediate medical attention:

While MCV does not always need immediate medical attention, there are several cases in which immediate medical attention becomes crucial. Consult a doctor immediately when experiencing: 

• Severe fatigue affecting daily activities

• Chest pain or difficulty breathing

• Rapid or irregular heartbeat

• Severe numbness or tingling

• Confusion or memory problems

Regular follow-up blood tests help track whether dietary changes or supplements are working effectively. Most people see improvements in their MCV levels within a few months of addressing the underlying cause.

Don’t Ignore the Signs: Get Checked from Home

Changes in MCV levels can be a crucial sign of anaemia, a condition affecting millions of people worldwide. Recognising the signs early and booking an MCV blood test can help prevent serious health issues before they become problematic. Modern healthcare facilities have made it easier than ever to stay on top of important health markers like MCV. With convenient at-home blood testing services, you can now track your blood health without disrupting your busy schedule or dealing with long clinic waits. At-home lab testing involves home collection of blood samples, saving you the time of a lab visit and providing accurate and reliable lab results conveniently at your doorstep.