Types of Autonomic Disorders
Physicians at NYU Langone’s Dysautonomia Center are experienced at recognizing the many types of autonomic disorders. The autonomic nervous system regulates the function of the body’s internal organs, such as heart rate, blood pressure, digestion, and body temperature. People with an autonomic disorder have trouble regulating one or more of these systems, which can result in fainting, lightheadedness, fluctuating blood pressure, and other symptoms.
Orthostatic hypotension is a sudden drop in blood pressure that occurs when a person stands up, causing low blood pressure in the upright position. This leads to a decrease in blood supply to the brain. The condition usually causes a person to feel dizzy or lightheaded. Sometimes, orthostatic hypotension can cause a person to faint.
Other symptoms of orthostatic hypotension include fatigue, particularly on exertion; vision problems; soreness in the back of the neck and shoulders, sometimes called “coat hanger” pain; or shortness of breath.
Symptoms are worse when people stand up and improve when they sit or lie down. Common causes of orthostatic hypotension include dehydration, hot environments, or standing for long periods of time. Most people feel better with hydration and rest.
Many people occasionally feel dizzy or lightheaded after standing. However, for those who feel lightheaded or lose consciousness every time they stand up, it could be a sign of an autonomic disorder.
Orthostatic hypotension can cause complications—especially in older adults—such as falling down as a result of fainting. People with the condition are at risk for bone fractures, stroke due to the reduced blood supply to the brain, or cardiovascular conditions such as chest pain or heart failure.
Postprandial hypotension is a sudden drop in blood pressure after a meal, caused by blood pressure changes while you’re digesting food. Symptoms include dizziness, lightheadedness, or fainting about 15 to 90 minutes after eating. The condition is common in adults over the age of 60 and people with other disorders of the autonomic nervous system.
During digestion, extra blood is diverted to the stomach and small intestine, causing the heart to beat faster and harder while blood vessels far from the digestive system narrow. These actions maintain blood pressure and blood flow throughout the body. However, in people with postprandial hypotension, the heart rate doesn’t beat as fast as needed and the blood vessels don't constrict as they should, so blood pressure drops.
Multiple System Atrophy
Multiple system atrophy is a rare autonomic disorder that typically affects men and women in their 50s and advances rapidly over the course of 5 to 10 years. The condition causes a progressive loss of motor function and, eventually, the need to use a wheelchair.
There are two different types of this condition: the cerebellar type and the Parkinsonian type. How a person is diagnosed depends on the most prominent symptoms at the time he or she is evaluated.
People with the Parkinsonian type have symptoms similar to Parkinson’s disease, such as moving slowly, stiffness, tremors, and problems with balance and coordination.
Those with the cerebellar type have loss of coordination, difficulty swallowing, speech problems or a quivering voice, and unusual eye movements.
This condition tends to progress more rapidly than Parkinson’s disease, and most people eventually require an aid for walking, such as a cane, walker, or wheelchair, within a few years of the onset of symptoms.
Pure Autonomic Failure
Pure autonomic failure is a rare degenerative disorder that causes orthostatic hypotension, sexual dysfunction, a decreased ability to sweat, elevated blood pressure when lying down, and changes in gastrointestinal and urinary habits. The condition affects men slightly more often than women, and is often found in middle-aged to older adults.
Afferent Baroreflex Failure
Afferent baroreflex failure is an autonomic disorder that causes fluctuations in blood pressure due to a failure of the blood pressure-sensing nerves that relay information to the brain. As a result, blood pressure alternates between being too high and too low. Symptoms include dizziness and fainting as well as headaches, sweating, and skin flushing.
The condition occurs when there is damage to the blood pressure-sensing nerves in the neck following cancer treatment, surgery, or radiation therapy. It can happen in people who have a stroke that affects the areas of the brain where blood pressure information is relayed. It can also be a result of hereditary disorders that affect the development of blood pressure-sensing nerves.
Familial dysautonomia is a rare inherited condition that affects the development of the autonomic and sensory nervous systems. People with this condition have unstable blood pressure that alternates between being too high and too low. They may also have reduced sensitivity to pain and temperature and an absence of tears when crying.
Other common symptoms include difficulty swallowing, severe vomiting or gastroesophageal reflux, poor muscle tone, excessive sweating, overproduction of saliva and mucus, and blotchy reddening of the skin when excited or eating. People with familial dysautonomia may develop chronic breathing problems due to reflux of stomach acid or food. They may also have vision problems due to progressive damage to the optic nerve in the eyes.
During times of stress, people with familial dysautonomia may experience dramatic high blood pressure and heart rate accompanied by vomiting or retching. This is known as an autonomic crisis.