Basal Body Temperature
The chemical and metabolic rate regulates and controls many body functions. Thyroid function is a major determinant of the metabolic rate. Blood tests such as thyroid hormone levels (T3, T4, T7, FTI, TSH, reverse T3, etc.) only measure the quantity of these hormones in the blood. The levels are compared to community averages but can not tell if the level or function is appropriate for your thyroid hormones. For example, the level of hormone may be within the "normal" range yet not be sufficient for your metabolic needs.
One way to get more information about the function of the thyroid gland is to perform functional tests. The Basal Body Temperature (BBT) is performed by you at home in bed first thing in the morning. Use a glass thermometer. Before you go to bed shake down the thermometer to below 95.0° and place it on top of your alarm clock. Set the alarm clock. When the alarm goes off in the morning, hit the snooze button and put the thermometer under your arm. Don't get up, go back to sleep until the snooze rings you awake again (usually 7-10 minutes). Read the thermometer and record the temperature on the chart below.
Please check your heart rate before getting out of bed. Take your pulse by placing two fingertips over the thumb side of your inner wrist area. As you feel the pulsations, count your pulse for 30 seconds. Multiply this amount by two and record the pulse rate on a chart. You might briefly list your symptoms if you had a good day, bad day, etc... For example, women should mark their ovulation (use "O") and menses (use "M").
Some causes of low body temperature and related symptoms:
- Hypothyroidism: low heart rate, slow movements, mental dullness, weight gain, high cholesterol, high blood calcium, rapid blood clotting. It is worth noting that low thyroid function does not always require hormone replacement (levothyroxine, Thyrolar®, Cytomel®, Armour Thyroid , NatureThroid, etc).
- Pituitary insufficiency: obesity, white skin, sluggish mentality, increased urination, lack of hair growth
- Gonadal insufficiency: - no hair growth, smooth thin skin, high-pitched voice, obesity, irregular menses, immature mammary glands
- Adrenal insufficiency: low cholesterol, hyperpigmented skin, low blood pressure, asthenia
- Hypoglycemia and other impairments of oxidative metabolism
- Pancreatitis (usually acute cases only)
- Recreational drug or alcohol abuse
- Central Nervous System abnormalities (severe and unusual types).
- Metabolic toxicity: if the mechanisms that produce energy (and thus the heat that keeps your body temperature above room temperature) are ineffective or blocked, it only makes sense that your temperature would be lower than expected.