Asthenia is a medical term that refers to a state of physical weakness or lack of energy. It is often characterized by fatigue, reduced strength, and a general feeling of tiredness. Asthenia can be a symptom of various underlying conditions, including infections, chronic diseases, or psychological issues. The causes of asthenia can vary widely, ranging from lifestyle factors such as poor nutrition and lack of sleep to more serious health problems like anemia or thyroid disorders. Treatment typically focuses on addressing the underlying cause and may involve lifestyle changes, medication, or therapy.