Complete Blood Count Test
A complete blood count ( CBC) is a blood test to evaluate a person’s health and detect various disorders, such as anemia, infection and leukemia.
Complete blood count is also often used to see the side effects of medication. Through this examination, health workers can measure several components and features of blood, such as red blood cells, white blood cells, hemoglobin, hematocrit to platelets.
An increase or decrease in the number of abnormal cells as revealed in a complete blood count may indicate certain medical conditions that require further evaluation.
Why Do a Complete Blood Count?
A complete blood count is often used as an important part of an annual physical exam. It is also often done to monitor the side effects of some prescription medications.
A doctor may also recommend a complete blood count for people who have blood disorders such as anemia or leukemia. Here are some other conditions that require a complete blood count:
- Routine medical check-ups. Your doctor may recommend a complete blood count as part of a routine medical check-up to monitor your general health and check for health problems, such as anemia or leukemia.
- Diagnosing a medical condition. Your doctor may recommend a complete blood count if you have symptoms such as fatigue, weakness, fever, inflammation, bruising or bleeding. A complete blood count can help your doctor diagnose the cause of your symptoms. This blood test is also recommended for people who suspect they have an infection.
- Monitoring medical conditions. If you have been diagnosed with a blood disorder that affects your blood cell count, your doctor may use a complete blood count to monitor your condition.
- Evaluating medical care. A complete blood count may also be used to monitor health after taking medications that can affect blood cell counts.
When to Do It?
Your doctor may recommend a complete blood count as part of a routine checkup or if you have unexplained symptoms, such as:
- Bruising or bleeding.
- Fatigue, dizziness or weakness.
- Fever, nausea and vomiting.
- Inflammation (swelling and irritation) in any part of the body.
- Joint pain.
- Problems with heart rate or blood pressure.
The above symptoms often indicate a blood disorder, such as anemia or leukemia.
It’s best not to delay the time to immediately do a complete blood count check that you can do at home!
How to Do It?
During the complete blood count test, the laboratory medical staff will draw blood from a vein, usually from the inside of the elbow or from the back of the hand. Then, the staff will take the blood sample with the following steps:
- Provide the skin with an antiseptic wipe.
- Applying an elastic band or tourniquet around the upper arm to help make the vein visible, then inserting a needle through it and collecting a blood sample in one or more vials.
- Removing the elastic band.
- Cover the injection area with a bandage to stop bleeding.
- Label the blood sample and send it to the laboratory for further analysis.
This blood count test only takes a few minutes and causes minimal discomfort. When the needle is inserted into your skin, you will usually feel a pinching sensation.
Some people may also faint or feel dizzy when they see blood. Afterward, the area of skin that was injected may bruise slightly, but usually, the bruise will disappear on its own within a few days.
Complete blood count results are usually available within a few hours to days after testing.
If the results of a complete blood count are above or below the normal range, it could indicate the following problems:
- If your red blood cell, hemoglobin, and hematocrit measurements are lower than normal, you may be anemic. Higher than normal red blood cell, hemoglobin, and hematocrit counts may indicate polycythemia vera or heart disease.
- A lower than normal white blood cell count can indicate a medical condition, such as an autoimmune disorder that destroys white blood cells, bone marrow problems, or cancer. Certain medications can also cause a low white blood cell count. A higher than normal white blood cell count often indicates an infection, inflammation, or immune system disorder. A high white blood cell count can also be a reaction to medication.
- A platelet count that is lower than normal (thrombocytopenia) or higher than normal (thrombocytosis) is often a sign of an underlying medical condition or may be a side effect of medication.