Symptoms of leukemia include fever or chills, persistent weakness, severe infections, losing weight, enlarged spleen, tiny red spots on the skin, bone pain and excessive sweating. The researcher could not find the exact cause of leukemia. But they think that it might be due to environmental and genetic factors. Due to mutations in the DNA, that instruct bone marrow to produce abnormal cells. These changes cause the cell to grow and divide abnormally. Over a period of time, these cells dominate healthy blood cells.