A complete blood count, shortened as CBC, is a common screening test that helps diagnose several health issues. A CBC checks if there is an increase or decrease in your blood cell counts. The normal CBC values depend on your gender and age.
A CBC test helps to diagnose a wide range of conditions, including infection, anaemia and cancer.
Your blood cell count can help your healthcare provider detect disorders and evaluate your overall health. It measures three basic blood cells. They include:
The red blood cells transport oxygen throughout the body and remove carbon dioxide from the cells to the lungs. A complete blood count test measures two components of the red blood cells
Haemoglobin – a protein that carries oxygen
Haematocrit – the red blood cell percentage in the blood
Low haematocrit and haemoglobin levels usually indicate anaemia, a condition occurring from iron deficiency in the blood.
White blood cells fight off infections in the body. A complete blood count can measure the types and number of white blood cells. An abnormal decrease or increase in the types or the number of white blood cells may indicate inflammation, infection or cancer.
Platelets aid blood clotting and control bleeding. When you have a cut, your platelets work to stop the bleeding, so any change in platelet levels may increase your risk of excessive bleeding. This may indicate a serious medical condition.
Your healthcare provider may order a CBC during your routine health check or if you experience unexplained symptoms such as bruising or bleeding. Complete blood count helps your doctor:
Doctors usually order a CBC to have a baseline view of your health or to screen for health conditions.
If you have symptoms such as swelling, bruising, bleeding, fever, tiredness, weakness or redness, your doctor will order a CBC.
Your doctor may order regular CBCs to monitor a health condition if the diagnosed condition can affect your blood cell counts
Some treatments can affect blood cell counts, which makes regular CBC necessary. Your CBC can help the doctor evaluate the effectiveness of your treatment.
Ensure you wear a shirt with a short sleeve or a sleeve you can easily roll up. You can eat before a CBC, but your healthcare professional may advise fasting for a specific period before the test. This may be the case if you need additional testing.
During your CBC, the healthcare professional will draw blood from your vein, usually from the back of your hand or inside your elbow. This takes only a few minutes with the following steps. The provider will:
The blood draw may be slightly uncomfortable. You may feel a pinching or prick when the needle enters your skin. Some people feel light-headed or faint at the sight of blood. After the blood draw, minor bruising may occur, but this clears within a few days.
You can get your CBC result within a few hours or a day after the testing.
For young infants, the nurse will sterilise the heel of the food and use a lancet to prick the sterilised area. The nurse will gently squeeze the heel to collect a small blood sample into the vial.
The test results vary based on sex. The following are the normal result range for adults, but the figures may vary slightly for different labs.
|
Blood component |
Normal levels |
|---|---|
|
Red blood cell count |
Men: 4.32 – 5.72 million cells/mcL Women: 3.90 – 5.03 million cells/mcL |
|
White blood cell count |
3500 – 10500 cells/mcL |
|
Platelet count |
150000 – 450000 cells/mCL |
|
Haematocrit |
Men: 38.8 – 50.0% Women: 34.9 – 44.5% |
|
Haemoglobin |
Men: 135 – 175 grams/L Women: 120 – 155 grams/L |
A complete blood count doesn’t give a definite diagnosis. A low or high blood count could indicate a wide range of conditions, so you will need specialised tests for a specific diagnosis.
Conditions that may cause abnormal complete blood count include:
If your CBC is below or above the normal range, the doctor may order additional tests to confirm your results. Further tests may also be necessary to confirm a diagnosis and evaluate your condition.
You can get a complete blood count test at Private Blood Tests London. Our healthcare professionals can advise you on the test needed. Visit our clinic today or call 02071830244 to schedule an appointment for your CBC test.