Blood Tests (Haematology)
Haematology is the part of the laboratory that studies the blood itself: the red cells that carry oxygen, the white cells that fight infection, the platelets and clotting factors that stop bleeding, and the blood groups that make transfusion safe. A few millilitres of blood can reveal anaemia, infection, bleeding problems and inherited conditions such as sickle cell disease.
In a hospital for mothers and children, haematology tests are part of almost every care pathway: antenatal follow-up, preparation for a caesarean section, the investigation of a feverish or pale child, and the follow-up of children with sickle cell disease. Our laboratory performs these tests every weekday and runs an on-call service for emergencies 24 hours a day.
What are haematology tests?
Haematology tests measure the number, size and appearance of blood cells and check how well the blood clots. The most common is the full blood count, which measures haemoglobin, red and white cells and platelets. Other tests include the erythrocyte sedimentation rate (ESR), examination of a blood film under the microscope, blood grouping, coagulation tests and haemoglobin electrophoresis. Your doctor chooses the tests according to your symptoms and situation.
- Tiredness, paleness or shortness of breath that may point to anaemia
- Fever or suspected infection in children and adults
- Routine antenatal care and preparation for delivery or surgery
- Unusual bruising, bleeding or heavy periods
- Follow-up of sickle cell disease and other chronic conditions
- Monitoring treatments that affect the blood
Good to know
The most common haematology tests
The full blood count (NFS) is the basic test and is often combined with a blood film, the ESR or a reticulocyte count. Blood grouping and Rhesus typing are needed in pregnancy and before transfusion, coagulation tests such as the prothrombin time check clotting, and haemoglobin electrophoresis identifies sickle cell disease and the sickle cell trait.
How the sample is taken
A nurse or laboratory technician takes blood from a vein in the arm, usually into small tubes with caps of different colours for different tests. For babies and young children only a small amount is needed, sometimes from a heel or finger prick. The procedure takes a few minutes, and a cotton pad pressed on the site stops any bleeding.
Understanding your results
Normal values depend on age and sex and change during pregnancy: a newborn's haemoglobin is naturally higher than an adult's, while a pregnant woman's is often slightly lower. The report shows reference ranges beside each result, but only your doctor can interpret them in the context of your health.