There are three types of nerves in your body: Autonomic, Motor, and Sensory nerves. The Autonomic nerves control involuntary or partially voluntary activities such as heart rate, blood pressure, and temperature control. The Motor nerves control movement by sending information from your brain or spinal cord to your muscles. Sensory nerves send information from your skin and muscles back to your brain so that you can feel pain and other sensations.
When nerves are cut or damaged they can cause pain, numbness, or other symptoms depending on where the damage has occurred.
Damage to the motor nerves may result in weakness, muscle wasting, twitching, or paralysis. Damage to the sensory nerves may produce pain, sensitivity, numbness, tingling, and/or burning.
Motor and sensory nerves can be damaged by compression or trauma. Long term problems such as carpal tunnel syndrome can cause compression and a simple cut to your finger, for example, can cause enough trauma to sever the nerve.
Often when nerves are damaged, your physician will recommend a surgical procedure to either decompress the nerve or to actually repair the nerve. This does not always completely cure the symptoms associated with nerve damage. Nerves regenerate at a rate of 2mm per day for small nerves and 5mm per day for large nerves. Symptom relief may take weeks or months depending on the injury.