The nervous system controls everything the body does, including breathing, digestion, movement of muscles and feeling sensations of heat and cold. there are three types of nerves in our body. Sensory nerves relay information from muscles and skin to brain which gives sensation of touch, pain and temperature. Motor nerves relay information from the central nervous system to the muscles and control the movement of the body. the autonomic nervous system controls the involuntary activities and also some voluntary activities of the body, including digestion and heart rate, blood pressure and temperature regulation. Nerve damage is injury of nerve fibres at any part of the body.

Nerve damage can be observed through various symptoms which are totally dependent on the three types of nerves as well as the location of the nerves that are involved. Nerve damage can occur in any nerves located in the central nervous system, spinal cord and peripheral nervous system. Three types of nerve damage symptoms are given below.

The following seven symptoms are due to damage of autonomic nerves:

• Dry eyes and mouth
• Too much sweating (hyperhidrosis) or too little sweating (anhidrosis)
• Lightheadedness
• Bladder dysfunction
• Constipation
• Inability to sense chest pain, such as angina or heart attack
• Sexual dysfunction

The following symptoms produce due to damage of motor nerves:

• Muscle atrophy
• Twitching, also known as fasciculation
• Paralysis
• Weakness

Sensory nerve damage may produce the following symptoms:

• Sensitivity
• Burning
• Pain
• Tingling or prickling
• Numbness
• Problems with positional awareness

Sometimes, a patient may experience more than one type of nerve damage. for example, one can have numbness and muscle atrophy simultaneously. All types of nerve damages can be categorized into three categories. All the symptoms of nerve damage are dependent on the following three types of nerve damage: neurapraxia, axonotmesis, neurotmesis.

Neuropraxia: it is caused due to increased pressure in nerves which are vital for cardinal functions. Increased pressure in nerves can block the neurotransmission, hampering proper functionality of the nerves. Loss of blood supply can also cause neuropraxia. this is a mild type of damage that can be recovered very quickly within days or months.

Axonotmesis: this type of damage is a less severe form of damage, which is caused either due to increased pressure of the nerves, which may cause them to be crushed. this type of damage is mainly due to the axons of the nerves keeping other parts intact. Nerves which have suffered this type of damage can regenerate over a matter of months.

Neurotmesis: this is the most dangerous form of nerve damage, which cannot be easily recovered from. Neurotmesis occurs due to severe bruising, stretching or tearing of nerves and surrounding tissue.

Apart from the above three types of nerve damage, there are some other situational types of nerve damage, for instance, diabetic nerve damage, which is caused due to glycosylation in nerves. almost two-thirds of diabetic patients are susceptible to diabetic neuropathy, a severe form of nerve damage.

The common symptoms for diabetic neuropathy are numbness in the extremities, pain, tingling sensations, atrophy of the limb muscles, sexual dysfunction, digestive symptoms as well as weakness. however, some people do not experience any noticeable symptoms at all even if they suffer from diabetic neuropathy.

There are many reasons behind the nerve damage of human body. they include autoimmune diseases, cancer, compression/trauma, diabetes, side-effects of drugs and toxic substances, motor neuron diseases, nutritional deficiencies and infectious diseases. by observing the symptoms and causes of nerve damage, a proper treatment plan can be devised easily.