Hematocrit
What is Hematocrit?
Hematocrit, also known as packed cell volume (PCV), is a measure of the proportion of whole blood volume that is occupied by red blood cells. It is expressed as a percentage, meaning that a hematocrit measurement of 40% indicates that 40% of the whole blood sample consists of red blood cells and 60% is composed of other components of blood, such as plasma. The higher the hematocrit reading, the greater the number of red blood cells.
Preparation for Hematocrit
Hematocrit is usually done as part of a routine complete blood count (CBC). A CBC is used to assess various components of a person’s blood, including red and white blood cells as well as platelets. There is no specific preparation required prior to the test. You may be asked to not eat or drink for several hours before the test.
Procedure for Hematocrit
To check hematocrit levels, a blood sample is drawn and placed into an apparatus called a hematocrit centrifuge. The centrifuge separates components of the blood by spinning the sample at high speed in order to separate the solid and liquid components. The red blood cells, which are heaviest, sink to the bottom of the tube and the other components, which are lighter, remain at the top. The hematocrit will be expressed as a percentage or a decimal.
Types of Hematocrit Levels
- A hematocrit level of 39%-50% is considered normal for adult males.
- In adult females, a hematocrit level of 36%-46% is considered normal.
- In children, the normal hematocrit level will vary depending on age and gender.
Risks of Hematocrit
Having a low hematocrit level, known as anemia, can be a sign of an underlying medical condition, such as a nutritional deficiency, kidney disease, or an autoimmune disorder. Having a high hematocrit level, known as polycythemia, can be a sign of an underlying medical condition, such as dehydration or cancer.
Why is Hematocrit Done?
Hematocrit is used to diagnose anemia and other conditions that affect red blood cell and platelet levels. It is also used in conjunction with other tests to detect bone marrow disorders and measure plasma volume in the body. In addition, hematocrit can be used to check for dehydration or dehydration-related illnesses.
When is Hematocrit Done?
Hematocrit is usually done as part of a complete blood count, which is typically done at least once a year as part of a regular health checkup. It may also be done when someone has signs or symptoms of anemia, such as fatigue or shortness of breath. It may also be done to monitor the hematocrit levels of people with conditions that can affect red blood cell or platelet levels.