One month after pituitary tumor surgery, body fatigue is considered to be related to the decrease of hormone level and hypokalemia. 1. Decrease in hormone level: for pituitary tumor surgery patients, the function of pituitary gland may decrease, the hormone level in the body decreases and the phenomenon of body weakness occurs. 2. Hypokalemia: one month after some pituitary tumors surgery, body fatigue is related to hypokalemia, which is related to the decrease of potassium intake, gastrointestinal loss, etc. Patients mainly have the symptoms of body fatigue and hypokalemia. The main manifestations of patients are weakness, muscle weakness, abdominal distension, arrhythmia, etc. Some patients with mild disease may be asymptomatic. It is suggested that patients with weakness one month after pituitary tumor surgery should consult a doctor for examination, and follow the doctor’s instruction to take medication after clarifying the cause of the disease, and should not abuse medicines or prescriptions on their own. Pay attention to rest, avoid overwork and lack of sleep, and also pay attention to the reasonableness of diet to ensure the balanced intake of nutrients.