Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Early on there are typically no symptoms. Later non-painful lymph nodes swelling, feeling tired, fever, or weight loss for no clear reason may occur. Enlargement of the spleen and anemia may also occur. It typically worsens gradually.Risk factors include having a family history of the disease. Exposure to Agent Orange and certain insecticides might also be a risk. CLL results in the buildup of B cell lymphocytes in the bone marrow, lymph nodes, and blood. These cells do not function well and crowd out healthy blood cells. CLL is divided into two main types: those with a mutated IGHV gene and those without. Diagnosis is typically based on blood tests finding high numbers of mature lymphocytes and smudge cells.Management of early disease is generally with watchful waiting. Infections should more readily be treated with antibiotics. In those with significant symptoms, chemotherapy or immunotherapy may be used. The medications fludarabine, cyclophosphamide, and rituximab are typically the initial treatment in those who are otherwise healthy.CLL affected about 904,000 people globally in 2015 and resulted in 60,700 deaths. The disease most commonly occurs in people over the age of 50. Males are affected more often than females. It is much less common in people from Asia. Five-year survival following diagnosis is approximately 83% in the United States. It represents less than 1% of deaths from cancer.