Body temperature can be an indicator of thyroid function
Our healthy body temperature is around 36.6 degrees Celsius or 97.88 Fahrenheit. It cannot deviate from that number too much and for too long. The human molecules and enzymes inside of the cells are designed to function around this magic temperature or otherwise they get irreversibly damaged.
We need adequate and regulated energy production to maintain our health. The whole body is involved in the regulation of our body temperature. However, the thyroid hormones play a major role in the energy production and temperature regulation. Thyroid gland is the first endocrine gland to develop in a fetus at four weeks of gestation as it drives the whole development of the embryo. The growing fetus uses maternal thyroid hormones also. Every baby is tested soon after birth for thyroid hormone levels to detect possible hypothyroidism. The treatment for hypothyroidism needs to be started as soon as it is detected. The baby who was born without a thyroid gland can only live for few weeks.
Without a thyroid hormone we would eventually stop moving, our muscles (including the heart muscle) would cease to work. There are some thyroid hormones analogues produced outside of the thyroid, like in the heart or the stomach but we primary need the thyroid hormones from the thyroid to keep us alive. In someone who had their thyroid removed, taking thyroid hormones is necessary. How long a person would survive without taking thyroid hormones after thyroid removal is dependent on the individual and the stress in their life. Thyroid hormones are stored in fat cells and will get used up over time, which may take about 6 weeks or slightly longer. After that the life will cease. A partially removed thyroid does not regenerate as the cell turn over in the thyroid is very slow.
Thyroid hormone T3 starts the process of energy production in the energy houses of our cells, mitochondria. T3 needs potassium mineral to initiate the production of the energy and life giving molecule, ATP. Other nutrients, especially vitamins B are also very important.
Adrenal hormones produced by small glands above your kidneys also play an important role in regulation of body temperature and generation of energy. Impaired adrenal function may result in body temperature changes. Individuals who are chronically stressed over a period of time tend to have some degree of adrenal exhaustion and produce lower levels of cortisol which can result in temperature fluctuations and lower body temperature. High levels of cortisol due to severe stress can raise body temperature temporarily.
The conversion of T4 into T3 is dependent on the availability of thyroid hormone nuclear receptors for binding of thyroid hormones, which in turn is mediated by the levels of cortisol (also called stress hormone). Adequate levels of cortisol and T3 hormone are important for maintaining a normal body temperature. Unfortunately, hypothyroidism may cause adrenal dysfunction. Nothing works well with low thyroid.
Hypothyroidism affects the body temperature more greatly than cortisol in general. A body temperature can be an indicator of a thyroid function, however blood tests are the accurate measure of thyroid hormonal levels. Body temperature it is not considered accurate test for determining thyroid function due to the fact that other factors can play a role in changing of the body temperature, such as certain illnesses, a reduced adrenal activity (and some degree of adrenal exhaustion) and even low blood sugar. Adrenals help to stabilize the body temperature and with a poor adrenal function, body temperature might be unstable. A slight increase of temperature also occurs in the middle of cycle, at ovulation time (around day 14) in women.
Anyway, it is good to be aware of your temperature and you can take your readings to your doctor. I had a lowered body temperature when I suffered with borderline low T3 hormonal levels while on a levothyroxine only hormonal replacement after my thyroid surgery.
Woman should measure their temperature from day 5 of the menstrual period and for three consecutive days. Non menstruating women and men can do this test at any time. You can only do the reading once at the time and do not repeat.
How to measure your basal temperature:
Measure your temperature as soon as you wake up while still in bed. Try not to move too much. Stay in bed for 10 minutes and record the temperature.
Digital thermometer is best for measuring underarm temperature. Oral thermometers are also considered to be very effective; you put them deep under the tongue. Mercury thermometers should not be used due to a danger of mercury toxicity. Ear thermometers are thought to be the least accurate for this purpose.
The normal underarm temperature is between 36.6 and 36.8 degrees C.
Anything below 36.6 degrees C (or below 97 F) might indicate hypothyroidism.
Anything above 36.8 degrees C (or 98.2 F) might indicate hyperthyroidism.
Oral readings are slightly higher, temperature of 37.0 degrees C (98.6 F) is considered normal.