Haematology is the study of blood and blood disorders. A haematologist is a specialist doctor with experience in the diagnosis and treatment of blood disorders, including blood cancers.
Types of blood cells
There are three types of blood cells: red blood cells, platelets and white blood cells.
- Red blood cells are the most common type. Their role is to move oxygen and carbon dioxide. They supply oxygen from your lungs to the rest of your body.
- Platelets help control bleeding by clotting your blood.
- White blood cells (leucocytes) are part of your immune system, which is how your body responds to infection.
Blood cells live and travel around your body in the bone marrow, blood vessels and the lymphatic system.
The bone marrow
Blood cells are made in the bone marrow. Bone marrow is on the inside of bones in the body, mostly in the pelvis, spine and sternum.
All blood cells come from stem cells. Stem cells multiply (copy) themselves and grow into different types of blood cells.
Immature cells multiplying out of control in the bone marrow cause acute leukaemias.
The lymphatic system
This system is a network of lymph nodes, blood vessels and organs (spleen, tonsils and thymus).
The lymphatic system helps return fluid (called lymph) from the blood vessels to other parts of the body where it’s needed. It helps us keep the balance of fluid right.
The lymphatic system is part of the immune system and defends us against infections. It helps lymphocytes (a type of white blood cell) travel to the lymph nodes to start an immune response. Your body has lymph nodes in the neck, armpits, abdomen (tummy) and groin.
B cell lymphocytes develop in the bone marrow. T cell lymphocytes develop in the thymus gland, in the chest area. When B cell lymphocytes mature (age), they can turn into plasma cells. Myeloma happens when plasma cells grow out of control in the bone marrow.