Normally, our nerves continuously transmit information from the whole body to the brain. If some information, for example about touch and pain, cannot be transmitted, we have a numbness in the affected area. This means that either a strange feeling is present throughout or a touch on the arm cannot be perceived as such. An example of this is that a leg has fallen asleep because too much pressure has been exerted on a nerve for too long. There are many different causes for this, most of which are completely harmless, but some of which must be treated directly.
Causes
The causes for numbness in the foot are manifold. One possibility is pressure on a nerve from outside, which is colloquially referred to as a numb foot. Deafness can also occur after insect bites.
After a tick bite, neuroborelliosis can also lead to numbness in the feet. Pressure on the nerve can also continue to develop centrally, for example when a nerve is pressed in by an intervertebral disc in the lumbar spine. A stroke can also lead to numbness in a foot or other parts of the body.
Multiple sclerosis can also initially manifest itself with numbness in an arm or leg. After an accident, numbness in the foot can indicate damage to the spinal cord. An accident can result in a severe impact on nerves.
This can be centrally located in the spine as well as on a single nerve in the leg. Bending the foot means that one side of the joint is stretched and thus all the structures running there are also under tension. This includes the sensitive nerves that transport touch information to the brain.
In rare cases, such nerves can even tear and thus lead to permanent numbness or paralysis. In most cases, however, the numbness that develops after bending is receding, and the swelling can only occur after the actual accident. Between the individual vertebral bodies of the spinal column there are cushioning discs, the so-called intervertebral discs.
These discs can be destroyed by incorrect loading and push in the nerves that leave the spinal cord. Depending on the height of the herniated disc, this can lead to pain and numbness in the affected areas. If there is numbness in the thigh, it can be a herniated disc of L2 or L3.
A herniated disc of L4 height affects the outer side of the thigh and the front inner side of the lower leg up to the big toe. In the case of L5, it is more likely to affect the outer side of the lower leg and the other toes, as well as large parts of the sole of the foot. S1 affects the little toe and runs along the outer edge of the sole of the foot, over the outer calf to the buttocks.
Numbness of the inner calf and the inner heel is caused by an incident at S2. If the symptoms are mild, those affected can already benefit from muscle strengthening and physiotherapy. In the case of more severe complaints and if paralysis occurs in addition to the numbness, surgery on the intervertebral disc may be necessary.
Polyneuropathy is a term which stands for many different nervous disorders. Those affected usually have numbness and sensations of discomfort in the feet or hands. The most common cause of this is diabetes, since high blood sugar levels lead to nerve damage.
Polyneuropathy can also be triggered by alcohol abuse, autoimmune diseases, poisoning and infectious diseases. Due to deafness, affected persons do not notice small damages, such as a stone in a shoe, and can therefore develop ulcers on the feet. Diabetics are therefore regularly tested for their perception of the feet.
A slipped disc can itself lead to a numbness in the toes, which does not have to be completely regressed even after an operation. However, a numbness can also occur as a complication of disc surgery. The surgery takes place in a very sensitive area near many nerves and an irritation of one nerve during the surgery can lead to later numbness. Immediately after the operation, the inflammatory reaction in the surgical area can also briefly exert pressure on the nerves.
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