What Are the Causes of Vagus Nerve Damage?

The vagus nerve originates in the brain stem and sends signals back and forth between the brain and internal organs. Chronic diseases such as diabetes can cause vagus nerve damage, as can trauma to the nerve. Smoking and drinking may exacerbate the condition. Vagus nerve damage can cause complications such as trouble swallowing or digestive problems.

About the Vagus Nerve

The vagus nerve originates in the medulla, a part of the brain stem, which is located in the lower back part of the brain. It is one of the longest nerves in the body, traveling from the brain to the colon. It supplies nerve fibers to the throat area, lungs, heart and digestive organs. It also takes signals from the internal organs and relays them back to the brain.


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Because the vagus nerve innervates the throat, damage to this nerve often results in problems speaking and swallowing. There is often a loss of the gag reflex as well. The vagus nerve also supplies nerve fibers to the stomach, and damage there can cause digestive difficulties such as loss of appetite or feeling full after eating a small amount of food.


Diabetes is a common cause of damage to the vagus nerve. The mechanism by which diabetes damages nerves is not fully understood. Any nerve in the body can be affected by diabetes. Another cause of vagus nerve damage is trauma to the vagus nerve. This can be caused by trauma to the body, such as a car accident, that puts pressure on part of the vagus nerve. Surgery also can put pressure on the vagus nerve and cause damage. Chronic illnesses such as HIV or Parkinson's disease also can cause damage to the nervous system, including the vagus nerve.


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Damage to the vagus nerve may cause gastroparesis, a condition in which the muscles of the stomach do not function normally. A healthy stomach contracts to move food down to the small intestine, and damage to the vagus nerve can interfere with this function, causing food to move slowly or stop moving entirely through the digestive system. Symptoms of gastroparesis include feeling full after eating a small amount of food, weight loss, heartburn and nausea. Medication and dietary changes can help resolve the symptoms of gastroparesis.


Chronic illnesses can cause damage to any nerve, including the vagus nerve, so people suffering from disorders such as diabetes should talk to a physician about the possibility of nervous-system complications. Smoking and drinking can exacerbate the nerve damage. It is important to consult with a doctor if symptoms of vagus nerve damage appear in order to receive the correct diagnosis and determine the underlying cause.