Left side limb weakness may be related to transient cerebral ischemia, cerebral hemorrhage, hypokalemia and other causes. 1. Transient cerebral ischemia: transient cerebral ischemia due to internal carotid artery stenosis and other reasons may lead to transient neurological dysfunction and symptoms such as numbness and weakness of the left limb. 2. Cerebral hemorrhage: cerebral hemorrhage may compress the nerves, and symptoms such as weakness of the left limb and limitation of movement may occur. 3. Hypokalemia: Hypokalemia due to insufficient potassium intake or diarrhea may cause symptoms such as left limb weakness and abdominal distension. It is suggested that people with left limb weakness should go to regular hospitals for consultation in time to clarify the cause of the disease and carry out standardized treatment under the guidance of doctors so as to avoid delaying the condition.