Increased heat of the body in conditions not of a fever is seen in many people. They feel hot and also
sweat a lot and have great discomfort due to this. The heat of the body may be due to a variety of
reasons.
The most important of these is the post-orthostatic tachycardia syndrome or POTS, which occurs due to
small imbalance in the functioning of the sympathetic nervous system and autonomous nervous system
of the body. When we get up from a lying or sitting position, the body experiences small variation in the
blood circulation in the body that leads to the feeling of heat in the body. This condition is seen more
commonly in women as compared to men. Women of 15 to 50 years’ age may experience this condition.
The condition called POTS may be associated with a variety of other symptoms in addition to feeling of
heat, sweating and great distress like vertigo, shakiness of the head, increase in blood pressure or
sudden drop in blood pressure, palpitation, heaviness in chest, unreasonable sweating, increased
burping, weakness, dizziness, and a desire to lie down. In 70% of the cases, these symptoms occur due
to increased tension, nervousness, anger, or lack of sleep, nightmares and following feeling of
discomfort, weakness, and wish to increase the fan speed, or walk around.
Investigation by a doctor would most often not reveal any disease condition and such people continue
consulting more doctors in order to find a diagnosis of their condition.
The second condition resulting in the increased heat, flushing and sweating of the body is as a side
effect of certain medicines such as painkillers, antibiotics, antivirals, hormonal therapies, chemotherapy
taken for diseases like cancer, etc.
The third major reason is increased tension, stress and anxiety disorder where there is quick release of
the stress hormone – adrenaline in the body. This may happen during an encounter with a sudden threat
such as a snake or a dog on the street. People who have increased stress and tension will have the
adrenaline released in blood without any specific reason and this leads to sudden increase in blood
pressure with a feeling of discomfort, rush of blood into the head, dizziness, vertigo, increased sweating,
palpitations etc.
The fourth condition that may lead to increased heat and sweat is anhidrosis which is a condition of
reduced sweating by birth. Such people would sweat slightly in the armpits or any other folds of the
body only even after strenuous exercise. Sweat is the natural mechanism in our body to regulate the
temperature of the body. When the temperature in the atmosphere increases, the body sweats to
prevent the increase in body temperature and water is excreted in the form of sweat. This water then
evaporates on the surface of our body and the body cools down. This is the normal cooling mechanism
of the body. But when the sweating is reduced, the release of heat and maintenance of body
temperature is not that easy and such people feel increased heat and flushing of the body.
The next important reason is the condition known as fibromyalgia, which is pain and inflammation of the
muscles of the body without any other underlying disease condition, where the muscles suddenly
contract and there may be increased heat, sweating and distress to the body. This feeling of heat is
relieved when the fibromyalgia is properly treated.
Diabetes is another important reason for heat, distress, weakness, frequent urination, increased thirst,
etc. in the body. When the sugar level in blood rises above a certain level, it creates a stressful situation
for the body and to overcome this, the liver and sweat glands work excessively and we get an increased
feeling of heat and sweat. Also, when diabetes is persistently not under control, the blood vessels,
nerves, and sweat glands do not function normally and the patients may have complaints like pain in the
limbs and neuritis. Similarly, when diabetes affects the sweat glands, the process of sweating may be
hindered and lead to increased heat and sweating in the body.
Increased heat and sweat may also be seen due to old age in people above the age of 65, as they find it
difficult to quickly adjust to the changes in the atmosphere and the body is unable to maintain the
thermostat.
The next major condition is the increased function of the thyroid glands known as the overactive
thyroid. Thyroid hormones play an important role in the production and utilization of energy in the
body, but in some people the thyroid glands work excessively and this leads to increased production of
energy in the body. This in turn causes palpitation, dyspnea, increased weakness, distress, excessive
emaciation of the body, reduced sleep, protrusion of the eyeballs, etc. This condition is known as
hyperthyroidism and there is a constant feeling of heat and sweating of the body in this situation.
Also, imbalance in the thyroid function like in case of autoimmune diseases, where the immune cells of
our body work against the thyroid gland and the functioning of the gland is impaired and the thyroid
peroxidase antibody in blood will be increased. So, if there is increased heat and flushing of the body, it
is advisable to check the thyroid hormone and thyroid antibodies.
Hormonal changes associated with menopause in women also causes flushing of the body, sweating,
heat, a feeling of fever, etc. after the age of 45 years and is known as the perimenopausal stage, which
begins almost 4 or 5 years before the actual menopause. Women have such symptoms due to the
reduction in the female hormones in the body. They may also experience palpitation, increased
weakness, vertigo, headache, etc. And some women become gloomy or depressed along with these
symptoms during the perimenopausal stage. They may also have persistent sweating, difficulty in
concentration, increased anger for small things, sudden bursts of crying, weakness of the body,
increased hair fall, wrinkling of skin, dryness of the vagina, constipation, difficulty in urination, irregular
menstruation or increased intermittent bleeding, swelling of any one part of the body like an arm when
waking in the morning, etc.
It is always advisable to meet a doctor to differentiate between these causes of heat intolerance and get
proper management of the symptoms with diet and medicine under the guidance of a doctor.