Tingling in the left hand and foot should be considered as a result of stroke, multiple sclerosis, spinal cord lesions, or a transient peripheral nerve dysfunction caused by malnutrition or overexertion. Tingling on one side of the arms and legs is often caused by lesions of the central nervous system. For example, acute cerebral infarction or cerebral hemorrhage in the sensory center of the right side of the brain may lead to numbness in the left side of the hands and feet. In the early stages of sclerosis, numbness of the left side of the hands and feet may be the only manifestation of the disease, which is caused by demyelination of the nerves in the brain and spinal cord. However, in addition to sensory abnormalities, the disease can also cause motor dysfunction of the limbs and autonomic neuropathy such as urinary and fecal incontinence. Acute myelitis and spinal cord tumors may also cause numbness on the left side of the arms and legs. This can be diagnosed by testing cerebrospinal fluid and doing an MRI of the skull and spinal cord to help diagnose it. If the numbness is caused by malnutrition, lack of sleep, or overwork, it will return to normal after some rest. If the above symptoms do not improve, it is recommended that the patient go to the hospital for a face-to-face diagnosis by a doctor.