Cachexia is a complex syndrome characterized by severe weight loss, muscle wasting, and a decline in overall health. It often occurs in patients with chronic illnesses such as cancer, chronic obstructive pulmonary disease (COPD), and heart failure. Unlike typical weight loss, cachexia involves a loss of both fat and muscle mass, which cannot be fully reversed by nutritional supplementation alone. The condition is driven by a combination of factors, including inflammation, metabolic changes, and hormonal imbalances. These factors lead to increased energy expenditure and decreased appetite, making it difficult for individuals to maintain their weight and strength. Early recognition and management of cachexia are crucial for improving the quality of life in affected patients.