Soft legs in the morning may be caused by physiological factors, or it may be a symptom of certain diseases, such as cold, cold, sleep apnea and hypoventilation syndrome, blood pressure changes, and so on. 1. Physiological factors: If you sleep too late the day before, or get up too early in the morning, as well as dreaming at night, easy to wake up, such as sleep deprivation or reduced quality of sleep, it can also lead to weak legs in the morning when you get up, weakness. 2. Pathological factors (1) Cold and flu: If you have a cold or fever at night, you often have obvious weakness or weak legs when you get up. (2) Sleep apnea hypoventilation syndrome: although such patients sleep enough, they can cause apnea at night because of central problems or peripheral airway obstruction, which leads to head hypoventilation and insufficient blood supply to the head. When these patients get up, they can have obvious weakness of the limbs, accompanied by dizziness, brain swelling and other discomforts. (3) Changes in blood pressure: As the blood pressure is low at 6 am, it then rises slowly. So it is necessary to judge whether the blood pressure is too low or too high according to the time when the patient gets up. Patients with too low or too high blood pressure may experience weakness in both lower limbs, dizziness in the head, or accompanied by headache and other symptoms. If the weakness of the feet in the morning persists without relief, it is recommended to go to the hospital for examination as soon as possible, and after the doctor clarifies the cause of the disease, targeted treatment will be given.