If the patient is suddenly weak and unable to stand, first of all, endocrine system diseases such as severe hypoglycemia should be excluded. Patients with hypoglycemia may experience general weakness, unsteadiness, or even cold sweat when they are hungry. If weakness and inability to stand occur slowly, cardiovascular and cerebrovascular diseases should be excluded, especially some lesions of cerebral blood vessels, such as insufficient blood supply to vertebral arteries or cerebral blood vessels, atherosclerosis of blood vessel walls and narrowing of the lumen, resulting in lack of oxygen to cerebral blood vessels, which often lead to weakness, slurred speech, dizziness, nausea and even coma of different degrees. In addition, some orthopedic disorders, such as spinal cervical spondylosis or tumors in the spine, may slowly cause the body to become unable to stand.