Numbness in the hands and feet can be caused by both temporary and medical reasons
Numbness that has a recent cause (for example, if you put pressure on your hands or feet for a while) or that subsides within a day or two is likely not an illness. If the numbness does not subside or gets worse, you may be concerned about an illness
Some conditions require immediate medical attention, so don't ignore them. Here we will explain the diseases that can cause numbness in the hands and feet
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Diseases suspected in numbness of the hands and feet
The causes of numbness in the hands and feet can be broadly divided into three categories: brain disease, spinal cord disease, and other diseases
brain disease
Because the brain is responsible for controlling the entire body, lesions (changes caused by disease) can cause movement disorders, including numbnessTypical examples include cerebral infarction, brain tumor, cerebral hemorrhage, cerebral contusion, and central hypothyroidism
In cerebral infarction, brain tumor, cerebral hemorrhage, and cerebral contusion,Numbness occurs in the limbs on the side opposite the affected area (right or left brain)It can also appear on one half of the face
The numbness will not go away on its own
In central hypothyroidism, if there is some abnormality in the pituitary gland in the brain, the secretion of thyroid-stimulating hormone from it decreases, and the secretion of hormones from the thyroid gland also decreases
Thyroid hormones are involved in metabolism, so if their secretion decreases, your hands and feet become more prone to swelling
As a result, the nerves in the hands and feet are compressed, causing numbness. In the hands, there is "carpal tunnel syndrome," which causes numbness in the entire thumb, index finger, and middle finger, and half of the ring finger. In the feet, there is "anterior tarsal tunnel syndrome," which causes numbness at the base of the thumb and index finger. Numbness usually occurs on both sides of the hands and feet, and tends to worsen when the hands and feet are overused①
All of the illnesses mentioned above are serious emergencies, so you should immediately seek medical attention or call an ambulance
reference)
Spinal cord disorders
The spinal cord is the nerve that sends commands from the brain to the limbs, so numbness can occur due to lesions in the spinal cord or the bones and ligaments surrounding the spinal cord
Typical examples include spinal cord tumors, cervical and lumbar disc herniation, ossification of the posterior longitudinal ligament, and spinal stenosis
Spinal cord tumors develop in the spinal cord or the spinal canal surrounding the spinal cord, causing numbness in the limbs or both. The numbness often does not subside
In cases of cervical or lumbar disc herniation, ossification of the posterior longitudinal ligament, and spinal stenosis, the intervertebral discs and posterior longitudinal ligament surrounding the spinal cord, as well as the spinal canal, become deformed, compressing the spinal cord and causing numbness in the arms or legs
The numbness varies depending on your posture. When you lean back or sit, your posture puts pressure on the spinal cord, making the numbness worse. Conversely, when you stand or look straight ahead, the pressure is reduced, making the numbness less severe
Regarding differences between the left and right sides, in all spinal cord diseases, the difference may be felt on only one side or on both sides, depending on the part and extent of the spinal cord that is compressed
The spinal cord also contains nerves that send commands for elimination, so if you are having trouble with elimination, it may be that the disease is progressing and surgery may be necessary. You should see a doctor immediately
Other illnesses
In other diseases, numbness occurs due to vascular, metabolic, or immune abnormalities that affect the peripheral nerves
Typical examples include diabetes, hypoparathyroidism, thoracic outlet syndrome, arteriosclerosis obliterans, and Guillain-Barré syndrome
In diabetes, substances that inhibit the function of nerve cells accumulate in the nerves, and the blood becomes thick and blood flow becomes poor, preventing oxygen and nutrients from reaching the tips of the hands and feet. As a result, you may feel numbness in the fingertips on both sides of your hands and feet
Thoracic outlet syndrome can cause numbness from the elbow to the little finger side in women with sloping shoulders or when the blood vessels and nerves that connect to the upper limbs from the chest to the shoulders are compressed for a long period of time.Numbness can occur on just one side or on both sides②There is no numbness in the legs
In hypoparathyroidism, the parathyroid glands are removed or damaged during thyroid surgery, which disrupts the parathyroid glands' ability to regulate calcium levels, resulting in numbness in the hands and around the mouth
In arteriosclerosis obliterans, arteriosclerosis of the blood vessels in the lower limbs causes inadequate delivery of oxygen and nutrients, resulting in numbness in the toes. In most cases, numbness is felt on both sides, but there is no numbness in the hands
In Guillain-Barré syndrome, a viral infection causes abnormalities in the immune system, leading to an attack on the body's own nerves, resulting in numbness in the hands and feet
One to two weeks after suffering from a cold or diarrhea, the patient suddenly experiences numbness and weakness in both arms and legs, and sometimes is unable to move the facial muscles③
The level of urgency varies for each of the illnesses mentioned above. If arteriosclerosis obliterans progresses, it may be necessary to amputate the lower limbs. Guillain-Barré syndrome can also be life-threatening if it affects the muscles involved in breathing. Seek medical advice or call an ambulance immediately. For other illnesses, follow the doctor's instructions and treatment to prevent numbness and the underlying illness from worsening
reference)
③Sudden symmetrical weakness and numbness in the limbs – Hyogo Medical Association (med.or.jp)
summary
This time, we talked about diseases that can cause numbness in the hands and feet
The location and type of numbness varies depending on the illness. In all cases, you should visit a medical institution to prevent the numbness or the underlying illness from worsening. If the condition is urgent, call an ambulance as soon as possible
Keep an eye on changes in your body and aim for a better life
Supervision: Dr. Yasushi Tsuda