Leukaemia is a cancer which starts in blood-forming tissue, usually the bone marrow. It leads to the over-production of abnormal white blood cells, the part of the immune system which defends the body against infection.
With leukaemia, the cancerous cells in the bone marrow spill out into the bloodstream
SYMPTOMS
Anaemia. This occurs as the number of red blood cells in the bloodstream goes down. This can cause tiredness, breathlessness and other symptoms. You may also look pale.Blood clotting problems. This is due to low levels of platelets in the bloodstream. This can cause easy bruising, bleeding from the gums and other bleeding-related problems.Serious infections. The abnormal white blood cells do not protect against infection. Also, there is a reduced number of normal white blood cells which usually combat infection. Therefore, serious infections are more likely to develop. Depending on the type and site of infection which develops, the symptoms can vary greatly.
The time taken to develop these symptoms after the disease starts varies. Typically, it is within weeks for ALL or AML. It may take months or years for symptoms to develop with CLL or CML, as these leukaemias progress slowly.
FINALLY: Leukemia develops when the DNA of developing blood cells, mainly white cells, incurs damage. This causes the blood cells to grow and divide uncontrollably. Healthy blood cells die, and new cells replace them. These develop in the bone marrow.