What is the
autonomic nervous system?
The autonomic nervous system (ANS) controls several basic functions,
You don’t have to think consciously about these systems for them to work.
The ANS provides the connection between your brain and certain body parts,
including internal organs. For instance, it connects to the heart, liver, sweat
glands, and even the interior muscles of your eye.
The ANS includes the sympathetic autonomic nervous system (SANS) and the
parasympathetic autonomic nervous system (PANS). Most organs have nerves from
both the sympathetic and parasympathetic systems.
The SANS usually stimulates organs. For example, it increases heart rate and
blood pressure when necessary. The PANS usually slows down bodily processes.
For example, it reduces heart rate and blood pressure. However, the PANS stimulates
digestion and the urinary system and the SANS slows them down.
The main responsibility of the SANS is to trigger emergency responses when necessary.
These fight-or-flight responses get you ready to respond to stressful
situations. The PANS conserves your energy and restores tissues for ordinary
What is autonomic dysfunction?
Autonomic dysfunction develops when the nerves of the ANS are damaged. This
condition is also called autonomic neuropathy or dysautonomia. Autonomic
dysfunction can range from mild to life-threatening. It can affect part of the
ANS or the entire ANS. Sometimes, the conditions that cause damage are
temporary and reversible. Others are chronic and may continue to worsen over
Diabetes and Parkinson’s disease are two examples of chronic conditions that
can lead to autonomic dysfunction.
of autonomic dysfunction
Autonomic dysfunction can affect a small part of the ANS or the entire ANS.
Some symptoms that may indicate the presence of an autonomic nerve disorder
- dizziness and fainting upon standing up, or orthostatic
- an inability to alter heart rate with exercise, or exercise
- sweating abnormalities, which could alternate between
sweating too much and not sweating enough
- digestive difficulties, such as a loss of appetite,
bloating, diarrhea, constipation, or difficulty swallowing
- urinary problems, such as difficulty starting urination,
incontinence, and incomplete emptying of the bladder
- sexual problems in men, such as difficulty with
ejaculation or maintaining an erection
- sexual problems in women, such as vaginal dryness or
difficulty having an orgasm
- vision problems, such as blurry vision or an inability
of the pupils to react to light quickly
You can experience any or all of these symptoms, and the effects may be mild
Orthostatic hypotension and a milder form of it called “orthostatic
intolerance” are two of the most common conditions that occur due to autonomic
dysfunction. Orthostatic intolerance occurs when your blood pressure drops as
you stand up. This can cause lightheadedness, fainting, and heart palpitations.
Symptoms such as tremor and muscle weakness may occur due to certain types
of autonomic dysfunction.
Types of autonomic dysfunction
Different types of autonomic dysfunction can vary in symptoms and severity,
and they can stem from different underlying causes. Certain types of autonomic
dysfunction can be very sudden and severe, yet also reversible.
Different types of autonomic dysfunction include:
Multiple system atrophy (MSA)
MSA is a fatal form of autonomic dysfunction. It has
symptoms similar to Parkinson’s disease, but has quicker progression. People with
this condition usually have a life expectancy of about five to 10 years
from their diagnosis. It’s a rare disorder that usually occurs in adults over
the age of 40. The cause of MSA is unknown, and no cure or treatment slows the
Postural orthostatic tachycardia syndrome (POTS)
POTS can affect both teenagers and adults. The symptoms can
range from mild to severe. People with mild symptoms can typically continue
with their daily lives, including going to school or work, and participating in
social and recreational activities. Those with more severe symptoms may
Possible causes for POTS include:
- multiple sclerosis
- mitochondrial diseases
- Lyme Disease
Neurocardiogenic syncope (NCS)
NCS is the most common type of autonomic dysfunction. Some
cases of NCS are fairly mild, with people rarely experiencing symptoms. Some
symptoms can indicate serious underlying health concerns. A sudden decline in
blood flow to the brain triggers fainting. Causes can vary, and injury from NCS
can often be as much of a concern as the cause behind it.
Hereditary sensory and autonomic neuropathies (HSAN)
HSAN is a group of related
genetic disorders that cause widespread nerve dysfunction in children and young
adults. Familial dysautonomia is in this group of diseases. HSAN often begins
in infancy. A symptom can be an inability to feel pain, and it can cause a loss
of feeling. A genetic mutation causes it.
Holmes-Adie syndrome (HAS)
HAS mostly affects the nerves
controlling the muscles of the eye, causing vision problems. One pupil will likely
be larger than the other, and it will constrict slowly in bright light. Deep
tendon reflexes, like those in the Achilles tendon, may also be absent. HAS may
occur due to a viral infection that causes inflammation and damages neurons.
The loss of deep tendon reflexes is permanent, but HAN isn’t life-threatening
or severely disabling.
Other types of autonomic dysfunction can result from disease or damage to
the body. Autonomic neuropathy refers to damage to nerves from certain
medications, injury, or disease. Diseases causing this neuropathy include:
Parkinson’s disease causes orthostatic hypotension and other symptoms of ANS
How is autonomic dysfunction treated?
Your doctor will treat autonomic dysfunction by addressing
the symptoms. They can treat orthostatic hypotension by suggesting lifestyle
changes and prescribing medication. The symptoms of orthostatic hypotension can
the head of your bed
compression stockings to prevent blood pooling in your legs
medications like midodrine
Your doctor will also treat the underlying cause such as alcohol
use disorder, diabetes, or Parkinson’s This may help slow the progression of autonomic
dysfunction. Nerve damage is difficult to cure. Physical therapy, walking
aides, feeding tubes, and other methods may be necessary to help treat more
Coping and support
Finding support to help you cope with autonomic dysfunction can be just as
important for improving quality of life as managing physical symptoms.
Methods for coping and improving quality of life include the following:
- Depression can occur with autonomic dysfunction.
Therapy with a qualified counselor, therapist, or psychologist can help you
- Ask your doctor or therapist about support
groups in your area. They’re available for different conditions.
- You may find that you have more limitations than
before your diagnosis. Set priorities to help you make sure you’re doing the
things that are important to you.
- Accept help and support from family and friends
if you need it.
- Ask for help if you need it.
Damage to the nerves of the autonomic system is often irreversible.
However, people with some conditions such as Guillain-Barré syndrome may have
significant recovery. Talk to your doctor if you have any symptoms of autonomic
dysfunction. Early diagnosis and treatment of the underlying condition can help
slow the progression of the disease and lessen symptoms. This can improve your
quality of life regardless of the severity of the condition.