Low Basal Body Temperature

Like heartbeat and blood pressure, body temperature helps assess the health of an individual. Human body temperature keeps on changing during various activities. Normal body temperature range for oral measurement is 98.2 ± 1.3 degree F, or 36.8 ± 0.7 degree C. Usually, the temperature is low in the morning and, as you start performing activities, it starts rising. The body attains the lowest temperature during sleep; which is referred to as basal body temperature (BBT). Despite drastic changes in the atmospheric temperature, the body maintains its normal temperature range with the help of brain, blood vessels, skin (sweat glands), etc.

Basal Body Temperature Measurement

As the body attains the basal body temperature during sleep, it is not possible to measure the actual BBT. Temperature measured immediately after waking up in the morning, before starting any activity (even before kicking off the sheets!), would give you the closest reading to the actual BBT. You can use a normal thermometer, or a basal body thermometer, to measure the temperature early in the morning. Even getting out of the bed, standing, can raise the body temperature, so you are supposed to measure it immediately after waking up. The basal thermometers show minute differences. A basal body temperature chart can help women know when ovulation has occurred. A woman can avoid pregnancy, or a woman can get pregnant soon, by keeping a record of basal body temperature during the menstrual cycle. BBT plays an important role in fertility treatments.

Low Basal Body Temperature Causes

Low BBT after Ovulation
The normal basal body temperature range is 97.8 to 98.2 degree F (for a person whose normal body temperature is 98.2 degree F); but it may vary slightly from person to person. Especially in women, significant variation in BBT during different phases of the menstrual cycle can be noticed. The hormones like estrogen, progesterone play an important role in raising or lowering the BBT in women. A rise in BBT around the middle of the menstrual cycle indicates that ovulation has occurred. This rise in temperature is attributed to the presence of the hormone progesterone released by the ovarian follicle. Low basal body temperature after ovulation indicates deficiency of progesterone. This results in difficulty in getting pregnant, or increases the risk of miscarriage.

Hypothyroidism
Low basal body temperature mainly indicates slowing down of enzymatic processes. Thyroid gland plays an important role in body metabolism. An under-active (slow functioning) thyroid can be the reason behind low BBT. Iodine deficiency, use of certain medications, pituitary disorder, thyroid gland surgery, pregnancy, radiation therapy, can lead to hypothyroidism. This condition needs proper medical attention.

Other Causes
There exist several other causes of low BBT. For example:

• Wilson's Temperature Syndrome: Excessive stress, shock can result in low body temperature.
• Over exposure to cold weather, frostbite
• Addison's Disease: Scarcity of adrenal gland hormones is responsible for low BBT.
• Endocrine dysfunction leading to hormonal imbalance
• Excessive alcohol or drug use can hamper the capacity of the body to maintain normal temperature.
• Being on cold intravenous fluids
• Being under the effects of anesthesia
• Diabetes (fluctuating/ high/ low blood sugar levels)
• Excessive consumption of certain medications like sedatives or diuretics
• Side effects of certain medications
• Surgery or accidents
• Dysfunction of the hypothalamus that controls body temperature.
• Liver or kidney failure
• Sepsis (very high level of bacteria in bloodstream due to widespread infection)
• Certain other chronic conditions like anemia, hepatitis C, cancer, etc.

It should be noted that temperature, one degree below the normal level, suggests that the body's enzymatic processes have slowed down by about 10%. Slowing down by 20% is considered as serious, and can prove to be life-threatening. The enzymes or hormones can function well with normal body temperature only.

Low basal body temperature can be noticed suddenly, or it can be persistent. Chronic low BBT can result in several health complications like excessive tiredness, headache, dry skin and hair, insomnia, acne, poor concentration, poor memory, depression, digestive system problems, bad breath, vision problems, ringing of the ears, irregular or no menstrual periods. Wearing warm clothes, following a healthy diet, exercising, can help raise the body temperature. Proper medications to treat the underlying condition, airway rewarming, cavity lavage can help bring back the temperature to normal levels. Delay in treatment can prove to be fatal in some cases.