Dysautonomia is an umbrella term for a group of neurological conditions that affect the autonomic nervous system (ANS), a vast network of nerves that maintain the body’s equilibrium (homeostasis). To do so, the ANS regulates many involuntary functions, including circulation, respiration, heart rate, digestion, kidney function, excretion, body temperature, perspiration, and pupil dilation.

Dysautonomia can cause problems by disrupting or distorting the messages sent and received by nerves in the ANS, which can lead to a variety of symptoms. Also known as autonomic neuropathy, dysautonomia is relatively common and estimated to affect more than 70 million people of all ages, genders, and races worldwide.

Types of Dysautonomia

There are at least 15 distinct forms of dysautonomia. The two most common are:

Postural Orthostatic Tachycardia Syndrome (POTS)

A blood circulation disorder, POTS can cause orthostatic intolerance, which is dizziness or fainting when sitting up from a prone position or standing up from a seated position. As gravity causes blood to settle in the lower body, the ANS is unable to properly regulate blood pressure by constricting blood vessels. As a result, blood flow to the brain is reduced. To compensate—and help ensure that sufficient blood reaches the brain—the ANS may elevate the heart rate, which can cause heart palpitations. Some people also experience fatigue, headaches, exercise intolerance, nausea, diminished concentration, shaking, and coldness or pain in their extremities.

Neurocardiogenic (Vasovagal) Syncope

Neurocardiogenic syncope occurs when the ANS overreacts to a stressful trigger, causing the heart rate to abruptly drop. In response to the slowed heart rate, blood vessels in the lower body widen, allowing blood to pool in the legs and lowering blood pressure. Because blood flow to the brain is reduced as a result, fainting or near fainting may occur. Possible vasovagal syncope triggers include extreme emotional distress, having blood drawn or the sight of blood, extended standing, fear of injury, and exposure to heat. While some people experience only a few fainting spells over their lifetime, others have several fainting episodes each day, which greatly increases their risk of falls and injuries.

Dysautonomia Symptoms

In addition to orthostatic intolerance and vasovagal syncope, dysautonomia can cause a variety of other symptoms depending on the body system it affects:

• Neurological system – Migraines, mental clouding, brain fog, and cognitive deficits
• Cardiovascular system – Heart palpitations, fast heart rate (tachycardia), slow heart rate (bradycardia), high or low blood pressure, chest discomfort, and blood pooling
• Pulmonary system – Shortness of breath and difficulty breathing
• Gastrointestinal system – Acid reflux, heartburn, nausea, vomiting, diarrhea, constipation, and abdominal pain
• Urinary system – Difficulty retaining and passing urine
• Pupillomotor system – Impaired vision and light sensitivity
• Secretomotor system – Difficulty sweating, dry eyes, dry mouth, difficulty swallowing, and dry skin

Dysautonomia symptoms can be sudden and unpredictable in onset, and they can range from mild to severe in intensity. To diagnose dysautonomia, a physician will typically review the symptoms, perform a physical exam, and possibly order diagnostic testing, such as blood work, a cardiac workup, and a tilt table test. Often used to investigate repeated and unexplained episodes of lightheadedness and fainting, a tilt table test can help the physician analyze the effects of different body positions on blood pressure, heart rate, and heart rhythm.

Dysautonomia Causes

Dysautonomia sometimes occurs on its own (primary dysautonomia) due to a genetic or degenerative condition that affects the brain or nervous system, or for unknown reasons (idiopathic dysautonomia). Dysautonomia can also occur secondary to another medical condition, such as diabetes, rheumatoid arthritis, celiac disease, lupus, multiple sclerosis, Sjogren’s syndrome, or Parkinson’s disease.

Dysautonomia Treatment

Currently, there is no cure for dysautonomia. In many cases, however, the symptoms can be effectively managed with a tailored treatment plan, which may include treating the underlying medical condition, if applicable. For instance, a diabetic should take proactive steps to keep their blood sugar levels within normal limits.

Many patients also benefit from:

• Drinking plenty of water every day to increase their blood volume
• Adding extra salt to their diet to help maintain normal fluid volume in their blood vessels and improve their blood pressure
• Achieving and maintaining a healthy body weight
• Avoiding extended standing and sitting
• Sleeping with their head raised about six to 10 inches above their body
• Taking medications to increase their blood pressure
• Wearing compression stockings and other supportive garments
• Taking cool or lukewarm baths or showers and avoiding extreme heat
• Quitting tobacco and minimizing their consumption of alcoholic beverages

It can also be helpful to stand up slowly and, if dizziness occurs, sit or lie down right away.

Talk With an Expert

If you would like to learn more about dysautonomia, you can talk with an expert in the cardiology department at Florida Medical Clinic. We see patients at several locations in the Tampa Bay area, including 14320 Bruce B. Downs Blvd. in North Tampa, 7760 Curley Rd. in Watergrass, and 2352 Bruce B. Downs Blvd. in Wiregrass. To request an appointment at any of these offices, click here.

About Paul Z. Gerczuk, MD

A graduate of St. George’s University School of Medicine, Dr. Gerczuk completed his internal medicine residency at the University of Southern California Keck School of Medicine. He went on to complete a cardiovascular research fellowship at The Heart Institute at Good Samaritan Hospital, a general cardiology fellowship at Allegheny General Hospital, and a cardiac electrophysiology fellowship at the University of South Florida. As a cardiac electrophysiologist and cardiologist, Dr. Gerczuk takes a special interest in diagnosing and managing heart rhythm disorders, and he has extensive experience in treating dysautonomia.