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.
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
These aspects of homeostasis are regulated through the autonomic
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
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.
Brain disorders such as traumatic brain injury can affect the
autonomic nerve system and result in dysautonomia: The autonomic
nervous system loses that balance and at various times the
parasympathetic or sympathetic systems inappropriately
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.
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
Essentially the treatment is to cool the
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
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:
- Tricyclic antidepressants
- Anti-anxiety medications
- Medications affecting high or low blood pressure and
- Non steroidal anti-inflammatory medicationsThe 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
References and further information