Full Blood Count medical test
Learn about Full Blood Count medical tests, including what the tests are used for, why a doctor may order a test, how a test will feel, and what the results may mean.
What is Full Blood Count?
A full blood count test looks at the number, types and sizes of different cells in your blood, including:
- red blood cells, which carry oxygen around the body.
- white blood cells, which fight infection.
- platelets, which help blood to clot.
It also measures haemoglobin, the protein that carries oxygen around the body and is found in red blood cells.
What the Full Blood Count test used for?
A full blood count is a very common test used to screen for, help diagnose, and monitor a variety of conditions. It can be used as part of routine medical testing, or to examine specific issues such as:
- infection
- anaemia
- tiredness or weakness
- bleeding or clotting problems
- exposure to toxic substances
- monitoring response to treatment
There are many medical conditions that can affect the full blood count. Blood cells can also be affected by some medications and some vitamin or mineral deficiencies.
How is the procedure performed?
A blood sample drawn from a vein in your arm. You may want to wear a shirt with sleeves that can easily be rolled up to make it easier to collect the blood sample.
What will be the results interprets?
The following are normal complete blood count results for adults:
| Red blood cell count | Male: 4.35-5.65 trillion cells/L*(4.32-5.72 million cells/mcL**) |
|---|---|
| Female: 3.92-5.13 trillion cells/L(3.90-5.03 million cells/mcL) | |
| Hemoglobin | Male: 13.2-16.6 grams/dL***(132-166 grams/L) |
| Female: 11.6-15 grams/dL(116-150 grams/L) | |
| Hematocrit | Male: 38.3-48.6 percent |
| Female: 35.5-44.9 percent | |
| White blood cell count | 3.4-9.6 billion cells/L(3,400 to 9,600 cells/mcL) |
| Platelet count | Male: 135-317 billion/L(135,000 to 317,000/mcL) |
| Female: 157-371 billion/L(157,000-371,000/mcL) |
- * L = liter
- ** mcL = microliter
- *** dL = decilite
- Red blood cell count, hemoglobin and hematocrit. The results of your red blood cell count, hemoglobin and hematocrit are related because they each measure aspects of your red blood cells.
- If the measures in these three areas are lower than normal, you have anemia. Anemia causes fatigue and weakness. Anemia has many causes, including low levels of certain vitamins or iron, blood loss, or an underlying condition.
- A red blood cell count that's higher than normal (erythrocytosis), or high hemoglobin or hematocrit levels, could point to an underlying medical condition, such as polycythemia vera or heart disease.
- White blood cell count.A low white blood cell count (leukopenia) may be caused by a medical condition, such as an autoimmune disorder that destroys white blood cells, bone marrow problems or cancer. Certain medications also can cause white blood cell counts to drop.
- If your white blood cell count is higher than normal, you may have an infection or inflammation. Or, it could indicate that you have an immune system disorder or a bone marrow disease. A high white blood cell count can also be a reaction to medication.
- Platelet count.A platelet count that's lower than normal (thrombocytopenia) or higher than normal (thrombocytosis) is often a sign of an underlying medical condition, or it may be a side effect from medication. If your platelet count is outside the normal range, you'll likely need additional tests to diagnose the cause.