Red blood cells (RBCs) help transport oxygen to various body parts. A low RCB count can lead to kidney and heart disorders, while a high count can lead to polycythemia, increasing the risk of a blood clot. Doctors recommend a hematocrit (HCT) test to determine whether a person has the right amount of these blood cells. Continue reading to learn about the significance of this test and what it involves.

Hematocrit: What is it?
A hematocrit is a test to determine the amount of RBCs per 100 ml of blood. A person with a hematocrit level of 50% has 50 milliliters (ml) of RBCs per 100 ml of blood.

RBCs give blood its distinctive red hue and carry oxygen throughout the body. A protein called hemoglobin in the RBCs binds to oxygen molecules. As a result, oxygen is easily transported by these cells from the lungs to different body regions. RBC production must be adequate to maintain the body’s physiological functions.

What is the ideal hematocrit range?
The reference ranges for hematocrit vary from lab to lab, but typically, the following values are considered normal:

Women: between 35 and 45 percent (the range for pregnant women may be closer to 34 to 47 percent)
Men: 40 to 50 percent
Kids over age one: 37 to 44 percent

Hematocrit values should be read with other findings from a CBC test. The ordering physician should analyze the data thoroughly because a slight change in hematocrit percentage is not always a serious health concern. To develop an appropriate diagnosis and treatment plan, the results of this test should be matched to other findings and the physical examination.

Symptoms of low hematocrit levels
The following signs and symptoms frequently appear in people with low hematocrit levels:

Pale skin
Weakness
Exhaustion or lack of energy
Irregular heartbeat
Cold hands or feet

These symptoms may indicate anemia, a condition with unusually low hemoglobin levels. Women are more prone to mild anemia than men, which is treatable. Severe anemia, however, may signify a serious underlying health issue that requires more intensive care. A low hematocrit percentage could also indicate bleeding, malnutrition, leukemia, too much hydration, and reduced amounts of folic acid, iron, and B12.

Symptoms of high hematocrit levels
The following are a few signs that accompany high hematocrit levels:

Flushed skin
Vision issues
Headaches
Enlarged spleen

These signs and symptoms point to polycythemia, a disorder in which the body makes too many RBCs. In this condition, the blood clots more readily and is thicker. Since polycythemia cannot be cured, treatment focuses on symptom control. The main objective is to prevent stroke and deep vein thrombosis (DVT), a blood clot typically developing in a deep vein of the leg.

How do physicians measure hematocrit levels?
A health expert may recommend a hematocrit test to determine whether a patient’s RBC count is affecting their health. A hematocrit test is usually a part of a complete blood count (CBC) test, which aims to achieve the following goals:

Count RBCs
Count reticulocytes (immature RBCs)
Determine hemoglobin levels
Measure the size and shape of RBCs
Count white blood cells (WBCs)
Count platelets

When recommending a blood test, the health expert will consider a patient’s age and health history.

Why is a hematocrit test useful?
This test measures the proportion of RBCs to total blood volume. In doing so, it frequently aids in diagnosing disorders like anemia. Reduced hematocrit levels are typically a symptom of decreasing RBCs or hemoglobin. If a health expert identifies lower quantities of these cells in the blood, they can recommend a treatment plan to increase the levels and prevent health complications.

A hematocrit test can also identify a high RBC count. When there are more RBCs in the blood than needed, it could indicate decreased blood volume or severe dehydration. Identifying high hematocrit levels can help experts develop a treatment plan to reduce the amount of these cells in the blood. However, as mentioned earlier, hematocrit blood tests are non-specific, so results must typically be evaluated in conjunction with other data from the physical examination and lab testing to make a diagnosis.

Individuals can undergo a hematocrit test as part of their routine health check-ups. However, a doctor may also recommend this test when treating an underlying health condition. For instance, a doctor may ask for periodic hematocrit tests to track the impact of chemotherapy on a patient’s bone marrow. It is imperative to speak with a healthcare professional to discuss the results of a hematocrit test and decide on any necessary next steps for additional examination or treatment.