A complete blood count test, also called CBC, is usually done during routine health check-ups. Since doctors always request a complete blood test, even for the simplest diseases, many people do not know its importance.
A complete blood count test is the primary test for diagnosing health issues. A healthcare provider will draw your blood from your veins to carry out a complete blood count test. This test involves several parameters in the blood to detect health disorders.
The blood contains some components, and the complete blood test checks these parameters to help the doctor diagnose an illness and identify the risk of different conditions. A complete blood count test can also determine when a treatment is effective or ineffective.
Types of blood cells
The complete blood test has several benefits, including evaluating the blood cells. This test measures the three types of blood cells, which include:
- White blood cells (WBCs)
The white blood cells help in fighting against infections. They serve as the body’s defence, capturing and destroying foreign organisms in the body. A complete blood count test checks the different WBCs and their number. WBCs have a specific number in the blood, but different health conditions can make the number vary. For example, if there is an infection, the number of white blood cells will be higher in the blood.
There are five types of WBCs, and each can increase in response to specific conditions. The number of white blood cells can also determine the efficacy of cancer treatment.
- Red blood cells (RBCs)
The RBCs transport oxygen in the blood throughout the body and help to remove carbon dioxide from cells. The metabolism of red blood cells occurs in the bone marrow, and their lifespan is 120 days. This means continuous production of red blood cells is necessary for the proper functioning of the body. Bleeding and other conditions can affect red blood cell production.
A CBC test measures two red blood cell parameters – haematocrit and haemoglobin. Haemoglobin is the RBCs’ component that carries oxygen, while the haematocrit is the number of red blood cells in the blood.
If the levels of these parameters are low, it indicates anaemia, a condition characterised by a deficiency in iron.
Blood platelets are the smallest component of the blood. They help in the blood clotting process, and their deficiency can cause excessive blood loss from cuts. Platelets seal the surface of wounds and cuts, but a small alteration in their number poses a high risk of excessive bleeding.
A complete blood count cell count measures the size and number of platelets in the blood.
Why do we need a complete blood count test?
CBC test checks for various health issues and helps in the following ways.
- The result can determine the overall health status
- It helps in diagnosing the main cause of health conditions. In cases where we experience unclear symptoms such as fever, dizziness or fatigue, a CBC test can identify the issue.
- During a treatment, monitoring the progress of the treatment is necessary, and a CBC test helps with this. Your doctor can recommend routine CBC tests during a treatment to know if the treatment is effective
Complete blood count test procedure
You can carry out a complete blood count test while fasting and without fasting. Although the test is usually done while fasting, your situation will determine the testing requirement, and the doctor will inform you of the right thing to do. The pre-testing condition for CBC test varies depending on the medical condition.
Your healthcare professional will draw blood from a vein inside your elbow or the back of your hand. Before drawing the blood, the attendant will clean the area using antiseptic and tie a tourniquet in your upper arm. Next, the attendant will insert a needle into the vein to collect your blood into a small container, remove the needle, untie the tourniquet and cover the area with cotton to prevent bleeding. The attendant will label the sample and send it to the lab for analysis.
What do CBC test results mean?
A CBC test may not give a final result about your health condition but give an idea of the condition. If you require further treatment, the doctor will request special tests.
However, an abnormal CBC test result may indicate any of the following.
- Heart problems
- Iron or vitamin deficiency
- Adverse reaction to something (allergy)
- Blood clotting problems
Understanding the importance of CBC is necessary as it helps in analysing various health issues. If your doctor prescribes getting a CBC test, feel free to visit here for a private blood test in London.