|MadSci Network: General Biology|
Measuring body temperature is not a easy as you might think. The usual method of putting a thermometer under the tongue requires that it be left in the right position and be left long enough to read accurately. Usually that takes 2 minutes. The average value for humans is 98.6 F. or 37 C. but there is some variability around that average. Half of the world will have average values below that number, half will have averages above it. The first thing to ask is whether the measurement is being done properly and with an accurate thermometer. There is also a natural variation during the day. Body temperature is lower in the morning and highest on average in the afternoon. Morning temperatures might be as low as 96.0 normally. Your question is about "96 degrees". By that do you mean 96.0? If a person's temperature was consistently below 96.0 degrees, it it probably below the "normal range". This can happen when a person is hypothyroid or with starvation. Here is a link to a page on hypothermia. It is mostly about hypothermia due to exposure to cold conditions, though: Hypothermia Other symptoms of hypothyroidism are dry skin, thin hair, changes in menstrual function, tiredness, thickening of the tongue and hoarseness. Hypothyroidism used to be tested by measuring "basal body tempreature", but there were a lot of incorrect diagnoses using that method. There is now a simple blood test for hypothyroidism, called TSH or thyroid stimulating hormone. When the thyroid is not able to make enough thyroid hormone, the brain's hypothalamus and pituitary release extra TSH to get the thyroid more active. High levels of TSH mean the brain thinks there is a low level of thyroid. In this matter, the brain is usually right. An exception the the "brain know right" occurs when the pituitary is not working right. The you can have a condition called hypopituitarism. It is a lot more unusual than hypothyroidism. David Winsemius, MD
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