Temperature Control and Dysautonomia - Fact Sheet

Cold-blooded creatures take on the temperature of their surroundings. They are hot when their environment is hot and cold when their environment is cold. Cold-blooded animals are much more active in warm environments and are very sluggish in cold environments. These animals are very dependant on their environment when compared to warm blooded animals like ourselves.

Warm-blooded creatures, like mammals and birds, try to keep the inside of their bodies at a constant temperature. They do this by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment. This independence from our environment allows warm blooded animals to live in a much broader variety of climates.

HOMEOSTASIS

It takes a lot of fuel to generate body heat and indeed a lot of fuel is needed to keep cool. Most of the food we eat is used to keep our bodies at a stable temperature with a stable amount of fluid of a stable composition.

Our bodies actually put a lot of effort into staying the same. The medical term for this process is homeostasis.

In human beings, the homeostatic regulation of body temperature involves such mechanisms as sweating when the internal temperature becomes excessive and shivering to produce heat, as well as the generation of heat through metabolic processes when the internal temperature falls too low.

The Autonomic Nervous System (ANS)

These aspects of homeostasis are regulated through the autonomic nervous system.

The autonomic nervous system manages most of our bodily systems, including the cardiovascular system, gastrointestinal, urinary and bowel functions, temperature regulation, reproduction and our metabolic and endocrine systems. Additionally, this system is responsible for our reaction to stress - the flight or fight response.

Sympathetic and Parasympathetic

The autonomic nervous system consists of two parts: the sympathetic system and the parasympathetic system. The sympathetic system can best be thought of as controlling the “fight or flight” reactions of the body; producing the rapid heart rates, increased breathing and increased blood flow to the muscles that are necessary when an individual is in danger or under stress. The parasympathetic system controls the “quiet” body functions, for instance the digestive system. In short, the sympathetic system gets the body ready for action, while the parasympathetic system gets the body ready for rest. And in most individuals the parasympathetic and sympathetic components of the autonomic nervous systems are in perfect balance, from moment to moment, depending on the body’s instantaneous needs.

DYSAUTONOMIA

A brain injury affecting the autonomic nerve system may result in dysautonomia: The autonomic nervous system loses that balance and at various times the parasympathetic or sympathetic systems inappropriately predominate.

Symptoms

Symptoms can include frequent, vague but disturbing aches and pains, faintness (or even actual fainting spells), fatigue and inertia, severe anxiety attacks, tachycardia, hypotension, poor exercise tolerance, gastrointestinal symptoms such as irritable bowel syndrome, sweating, dizziness, blurred vision, numbness and tingling, anxiety and (quite understandably), depression.

A person suffering from dysautonomia may exhibit all these symptoms and more or only one or two.

It can be an acute, short lived problem or a chronic problem that will last a lifetime.

There is no cure for dysautonomia but some medications and strategies can help alleviate the symptoms.

Management Strategies

The homeostatic regulation of body temperature may be severely impaired in a person suffering from dysautonomia and they may develop excessively high body temperatures and consequent irritability, confusion and disorientation. The treatment for a high temperature as a result of a damaged autonomic nervous system is entirely symptomatic and supportive. That is: the fever is treated but not the cause. Remember the cause is unfortunately incurable.

Essentially the treatment is to cool the person down.

A wet towel across the neck can be of help as most of our body heat is lost through the head and the external carotid arteries carry large amounts of blood to the brain. Cooling this area will effectively cool the whole body from the inside out.

Drink plenty of fluids, preferably water. Other fluids, particularly alcohol or caffeine, can reduce the fluid levels in the body by increasing fluid loss through sweating or urination.

It is essential to seek medical assistance if any fever is severe or prolonged as the fever itself may damage organs including the brain, heart and kidneys.

A host of medications have been tried in patients with dysautonomia. Those most commonly felt to be useful include:

The most effective medications will vary from person to person depending on the particular symptoms that dysautonomia produce in them.

As with any long-term health condition, it is highly recommended that a relationship be maintained with a GP or other suitable medical professional.

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