Fatigue Syndrome, often referred to as Chronic Fatigue Syndrome (CFS), is a complex disorder characterized by extreme fatigue that doesn't improve with rest. This fatigue can be debilitating and may worsen with physical or mental activity. The exact cause of CFS is unknown, but it may involve a combination of factors, including viral infections, immune system issues, and hormonal imbalances. Symptoms of Fatigue Syndrome can vary widely among individuals and may include sleep disturbances, cognitive difficulties, and muscle pain. Diagnosis is primarily based on patient history and symptom evaluation, as there are no specific tests for CFS. Treatment typically focuses on managing symptoms and improving quality of life.