HCT (hematocrit) test measures the percentage of red blood cells in the blood. Red blood cells help carry oxygen across the body. Too many or too few RBCs in the blood can lead to a few diseases. Also known as the packed-cell volume, the hematocrit test is a simple blood test. A healthcare provider might recommend the hematocrit test as a part of regular health checkups when undergoing cancer treatment or having any ongoing health condition.

What is the hematocrit test used for?
The hematocrit test is a component of the CBC, or complete blood count, a routine blood test used to measure different blood components. It is done to diagnose any blood disorders, including anemia, polycythemia, etc., and helps monitor one’s general health. It is an easy and secure process.

What are the normal hematocrit levels?
Different institutions will define the normal hematocrit range differently. But in the cross-population 2017 study, the following levels are specified to be normal:

Children – 30 to 44%, depending on their sex and age

Female – 37 to 47%

Males – 42 to 52%

Newborn babies will have higher hematocrit levels. But it will gradually decline as they grow older. Those who recently underwent a blood transfusion will show a difference in their results. Further, pregnant women have lower RBC levels than the typical range as the body tends to expand its blood volume during pregnancy. Another factor that may push levels into a higher range is chronic pulmonary disease.

What does it mean when the hematocrit levels are high?
Some other conditions that may lead to high hematocrit levels are:

Dehydration
Dehydration reduces the body’s water content and the plasma in the blood. Low plasma levels can increase the RBC-to-blood volume ratio. It leads to a spike in hematocrit levels.

Heart disease
Studies suggest that high hematocrit levels aggravate one’s risk of developing cardiovascular diseases.

Obstructive sleep apnea
Reports suggest a link between high hematocrit levels and obstructive sleep apnea.

Testosterone use
It amplifies the RBC numbers and increases the hematocrit levels.

Thickening or scarring of the lungs
Thickening or scarring of the lungs makes it challenging for the RBCs to carry oxygen across the body.

Carbon monoxide poisoning
Carbon monoxide has a devastating level on the capillaries. It reduces the plasma in the blood and increases the RBC count. More RBC leads to higher hematocrit levels.

Symptoms
Some common symptoms one may experience when the hematocrit levels are high include:
Dizziness
Flushed skin
Headaches
Vision issues
Enlarged spleen

When the hematocrit levels are higher than the typical range, they may cause adverse impacts and indicate a serious underlying health condition like heart disease, lung disease, kidney issues, etc.

What does it mean when the hematocrit levels are low?
Suspected anemia is the most prevalent reason for low hematocrit levels. However, the following conditions may also lead to a decline in the hematocrit levels:

Thyroid disease
The thyroid hormones help with RBC production. Lower RBC levels mean lower hematocrit levels.

Leukemia
At times, low RBC levels are also a symptom of leukemia. It means the cells in the bone marrow displace healthy RBCs.

Hyponatremia
Hyponatremia is a condition wherein one has excess water in the body, resulting in the blood being watered down.

Blood loss because of an injury or illness
Blood loss also declines the RBC levels, leading to low hematocrit levels.

Kidney disease
Low RBC levels indicate anemia, a common complication in kidney disease.

Hemolytic anemia
Hemolytic anemia means the RBCs are dying or breaking down faster than the body can replace them.

Symptoms
Some common symptoms one may experience when the hematocrit levels are low include:
Weakness
Pale complexion
Fatigue
Shortness of breath
Cold hands and feet

In women, hematocrit levels below 35%, and 41% in males are considered low. It is a sign of chronic anemia.

Balancing levels
The RBC count can be increased by fortifying one’s meal plan with iron-rich foods like spinach, beans, whole wheat bread, peas, tofu, and broccoli if the test results indicate anemia or iron deficiency. One can also take iron supplements. A person may require a blood transfusion if the anemia is severe. However, if one has a condition resulting in RBC overproduction, the healthcare provider may recommend adopting a heart-healthy meal plan.