There are three principal types of nerves in the body. Sensory nerves are the ones which send information to our brain regarding our tangible environment, and they comprise our sense of touch. Motor nerves send information to muscles which govern our voluntary movements. Our autonomic nerves control involuntary body functions like our heartbeat. Nerve damage is any kind of injury, whether minor or severe, that occurs to nerve fibers in any area of the body. Various causes can be responsible for damage to the nerves, which generally presents in one of three forms: neurotmesis, neurapraxia, and axonotmesis.
Dozens of different types of nerve damage exist, but almost all of them can be described by one of the three above categories. Neurotmesis is the most severe form of damage, which results in a complete loss of function and nerve continuity. It can be caused by severe bruising, tearing, or stretching of the nerve or surrounding tissue.
Axonotmesis is a less severe form of nerve damage, mainly seen as a result of injuries where the nerve is crushed or placed under too much pressure. The axon of the nerve is disrupted, but the nerve's structural integrity remains intact. This type of injury allows for the possibility of regeneration, which can take months or years to be complete.
Neurapraxia is the mildest type of damage, and usually allows for complete recovery within days or months. It is usually a result of pressure on a nerve which keeps it from functioning, and blocks the transmission of signals. Loss of blood supply may also cause neurapraxia.
The specific situational causes of nerve damage are as varied as the disorders that humans suffer from. Some conditions, however, are well-known for their ability to damage nerves. Diabetes is foremost among these, often causing the type of nerve damage called diabetic neuropathy. This term is nonspecific and refers to many types of nerve injury brought about due to diabetes. About two thirds of people with diabetes suffer from some form of neuropathy.
The symptoms of diabetic neuropathy can strike any part of the nervous system, but there are some common signs to look out for. Pain, tingling sensations, and numbness in the extremities, as well as muscle atrophy in the feet and hands are some of the classic signs of this form of nerve damage. Digestive symptoms and sexual dysfunction, as well as an overall weakness, are also somewhat common for neuropathies of this type, although many people who suffer from it experience no noticeable symptoms at all.