Dysautonomia is a broad term for conditions that range from fainting to more serious life threatening conditions. Some are quite common, and some are extremely rare.

Dysautonomia is a nervous system disorder that affects involuntary functions, such as breathing, blood pressure, and heart rate. It’s a broad condition that can involve too much or too little activity in the autonomic nervous system (ANS), which can affect your body in multiple ways.

For this reason, experts break dysautonomia down into different types. Here are 15 types to know about, including their symptoms, causes, and outlook.

POTS is primarily known for causing orthostatic intolerance, or a decrease in blood flow to the heart when you stand up. This can lead to a temporary increase in heart rate and lightheadedness of fainting.

Though POTS primarily affects people assigned female at birth ages 15–50, anyone can develop it. Experts estimate that POTS affects at least 500,000 people in the United States.

The exact cause of POTS isn’t known, though medications and increased sodium intake may help.

Orthostatic hypotension, or low blood pressure when standing up, is relatively common. It’s usually due to standing up too quickly.

Risk factors may include being an older adult, long-term bed rest, and dehydration. Certain chronic conditions like diabetes might also be a risk factor.

Primary orthostatic hypotension is a rare subtype of this condition related to dysautonomia. A doctor may run tests, such as blood pressure readings and EKGs, to determine the cause.

Dietary changes, hydration, and medication adjustments may all help control symptoms.

Vasovagal syncope is a fainting episode in response to triggers your body overreacts to. These may include phobias, significant stress, or seeing needles or blood. It’s relatively common, with an estimated lifetime incidence of 35%.

With vasovagal syncope, your blood pressure drops so suddenly that you may temporarily lose consciousness. Nausea, lightheadedness, and tunnel vision are also common symptoms. The best treatment for these episodes is trigger avoidance.

You may also prevent a vasovagal episode by lying in the supine position as soon as you experience warning signs.

FD is a genetic type of dysautonomia most often present at birth. It’s rare, affecting an estimated 200,000 people in the United States.

Common symptoms of FD include difficulties with breathing and swallowing, as well as poor blood pressure and body temperature regulation.

FD may worsen over time and may become life threatening during childhood. There’s no cure, but treatment can help alleviate symptoms and prevent complications. These include feeding tubes and corrective surgeries.

PAF is a rare neurodegenerative disease that affects an estimated 5,000 U.S. adults. It’s primarily characterized by symptoms of orthostatic hypotension, though it can also cause sleep disorders, bladder issues, and uncharacteristic sweating.

PAF may worsen over time and increase your risk of developing Parkinson’s disease, atrophy, or Lewy body dementia.

MSA is a neurodegenerative disorder that affects your autonomic and central nervous systems. Its hallmark symptom is autonomic dysfunction. MSA is sometimes called atypical Parkinsonian disorder.

Signs of MSA may include tremors, body stiffness, fainting, coordination problems, and bladder control issues. This condition usually develops in adults over age 50 and may progress quickly.

Some people with PAF may develop MSA.

IST is a type of sinus tachycardia in which there’s no clear cause. It’s most common in people assigned female at birth younger than 45.

Common symptoms include a resting heart rate of more than 100 beats per minute, heart palpitations, dizziness, and anxiety. Treatment may include beta-blockers and calcium channel blockers.

Like other autoimmune diseases, AAG occurs when your body attacks healthy cells and tissues. In this case, your body attacks the ANS. This rare condition usually develops in adulthood.

Possible symptoms of AAG include orthostatic hypotension, dry mouth, and fainting. You may also have issues with urinary retention and constipation. Doctors typically treat AAG with steroids or other immunosuppressive medications.

Baroreflex failure is a rare but serious fluctuation in blood pressure. Common symptoms include unexplained headache, sweating, and heart rate changes.

With this disorder, you may have periods of severe high blood pressure (hypertension) and increased heart rate in response to physical activity or emotional stress. You could also experience episodes of hypotension during times of rest.

HSAN refers to a group of rare disorders that damage nerve cells around the brain. There are five subtypes of HSANs based on different inherited genetic mutations. These also primarily develop during childhood.

HSANs present with varying degrees of autonomic dysfunction, such as gastroesophageal reflux, excessive sweating, or low blood pressure upon standing.

All HSANs include sensory dysfunction, such as depressed reflexes and altered pain and temperature perception. Other symptoms may include hearing problems and bone infections (osteomyelitis).

Autonomic dysreflexia is an overreaction of the ANS that may be life threatening. Spinal cord injuries are the primary cause. Up to 90% of people with such injuries are at risk of developing autonomic dysreflexia.

Symptoms may include hypertension, severe headaches, visual disturbances, cool skin, and severe anxiety.

This type of autonomic neuropathy occurs in people with diabetes. It primarily affects your cardiovascular system, gastrointestinal tract, urinary tract, and genitals.

Complications of diabetic autonomic neuropathy include diarrhea, urinary tract infections (UTIs), and erectile dysfunction (ED). In addition to diabetes management, doctors may recommend treatments for each specific symptom.

CCHS is a rare condition that causes breathing problems. It’s due to problems with autonomic control of breathing and global dysautonomia, which is autonomic dysfunction in several body systems. Doctors have identified about 1,000 cases of CCHS, with detection occurring at birth or during early childhood.

Symptoms of CCHS primarily involve taking shallow breaths, especially during sleep. This can cause carbon dioxide to build up in the blood, causing physical and developmental problems in children.

PSH is a type of dysautonomia usually due to a traumatic brain injury (TBI). Symptoms typically appear within 1 week of injury. It affects as many as 1 in 10 people with TBIs and can extend hospital stays by up to 2 weeks.

PSH often causes an increase in heart rate, blood pressure, and body temperature. You may also find yourself taking deeper, more rapid breaths, and sweating a lot. PSH episodes last about 30 minutes on average.

Treatment aims to manage symptoms and prevent further episodes. A doctor may prescribe beta-blockers or gabapentin. They may also monitor your diet and hydration.

Postprandial hypotension is when your blood pressure drops after a meal. Common symptoms include weakness, dizziness, chest pain, and nausea. You may also experience visual disturbances like eye floaters and have difficulty walking or standing.

Several types of dysautonomia can cause postprandial hypotension, though it’s possible to develop it without other ANS problems. It’s especially common among older adults. Other risk factors include heart disease, diabetes, and kidney failure.

Drinking water before meals or taking a 10-minute walk after meals may help relieve symptoms. A doctor may also recommend octreotide, vasopressin, or nonsteroidal anti-inflammatory drugs (NSAIDs).

Dysautonomia broadly refers to conditions that affect the autonomic nervous system. This can lead to involuntary symptoms that affect your blood pressure, breathing, and more.

Though many of the aforementioned types of dysautonomia are rare and genetic, it’s essential to talk with a doctor about other possible risk factors, such as diabetes or Parkinson’s disease.