Chronic myelogenous leukemia (CML) is a type of cancer that affects the blood and bone marrow. It occurs when the body produces too many abnormal white blood cells, which can crowd out healthy cells. CML is often linked to a genetic change called the Philadelphia chromosome, which plays a key role in the disease's development. Symptoms of CML may include fatigue, night sweats, and an enlarged spleen. The disease typically progresses slowly and can be managed with targeted therapies, such as tyrosine kinase inhibitors. Early diagnosis and treatment are important for improving outcomes and quality of life for patients.