Leukemia is cancer that affects the blood, lymphatic system and bone marrow, the soft inner part of bones where new blood stem cells are formed. Normally, the stem cells gradually mature into healthy red blood cells, white blood cells and platelets, which circulate throughout the body and perform many vital functions, such as transporting oxygen and nutrients.
Leukemia develops when the DNA of developing blood cells is damaged. As a result, the blood cells grow and divide uncontrollably, crowding out healthy blood cells in the bone marrow and potentially spreading to other parts of the body.
Leukemia is a complex form of cancer that has several types, which are determined based on the blood cells affected (myeloid or lymphoid) and the rate of cancer progression (acute or chronic).
Acute leukemia prevents blood stem cells from maturing. The condition progresses very rapidly, creating a large number of abnormal white blood cells that do not function properly.
The symptoms of acute leukemia, which tend to appear earlier and be more severe than the symptoms of chronic leukemia, can include:
- Unexplained fatigue
- Unintended weight loss
- Fever with no obvious cause
- Shortness of breath
- Pale skin (due to anemia)
- Tiny red spots under the skin
- Frequent infections that resist treatment
- Easy bruising and bleeding
- Slow-healing wounds
- Bone and joint pain
Chronic leukemia inhibits the development of blood stem cells, ultimately causing them to function less effectively than healthy mature blood cells. As compared to acute leukemia, chronic leukemia tends to be less severe and progresses more slowly. As the cancer spreads, symptoms may appear, such as:
- Lumps in the neck, armpits or groin (caused by swollen lymph nodes)
- Pain or a sensation of fullness in the belly (due to an enlarged spleen or liver)
- Fever, chills and night sweats
- Weakness and fatigue
Treatment for leukemia can vary based on its type. Therefore, an early and accurate diagnosis is essential to achieve the best possible outcome and quality of life.
Medically reviewed by Chetasi Talati, MD, Malignant Hematology.