The vagus nerve, which runs from the stomach to the brain, can become damaged in a number of different ways. One of the most common forms of damage is caused by hormonal imbalances. Physical damage, either from injury or surgery, can also cause impairment. Some patients may also have damage as the result of a viral or bacterial infection or a cancerous growth at any point along the length of the nerve. The result of any of these types of vagus nerve damage is often decreased function of the digestive system.
Diabetes is one of the most common causes of damage to the vagus nerve. Patients who have had this disease for a long time can experience damage to nerves throughout the body, often because of improper blood flow. Without enough blood, the vagus nerve can become permanently impaired. Cancer can also cause damage to the nerve, and tumors in the brain or that interfere with blood flow to the nervous system can damage it as well.
It is also possible for the vagus nerve to sustain an injury from trauma to the patient's body. The nerve is buried deep within the body and brain, so substantial damage must be done to a patient in order for the nerve to become injured. More frequently, patients who undergo surgery of the brain or digestive system can have it accidentally damaged.
Alcoholism can lead to another type of vagus nerve damage. Patients with this disease may experience a deterioration of nerve function throughout the body. In many cases, however, the damage is reversible if the patient stops drinking.
Some types of nerve damage are caused by infection. Viruses have been known to spread from the ears, nose, and throat to the vagus nerve, which runs behind these organs. A viral infection may be difficult to treat and could lead to irreversible damage to the nerve. Bacterial infections can also spread to the vagus nerve, though these infections can often be treated through the use of antibiotics.
Any type of vagus nerve damage can lead to gastroparesis. Patients with this condition have reduced gastrointestinal mobility because the vagus nerve is responsible for diverting enough blood to the digestive system so that it can process food quickly and efficiently. In patients with irreversible damage to the nerve, this condition can be controlled medically, though it cannot be cured.