Hyperthyroidism (pronounced: hi-per-thigh-roy-dih-zum). Hyperthyroidism is caused by an overactive thyroid gland. The thyroid releases too much of the hormone thyroxine, which increases the person's basal metabolic rate (BMR). It causes symptoms such as weight loss, increased heart rate and blood pressure, protruding eyes, and a swelling in the neck from an enlarged thyroid (goiter). The disease may be controlled with medications or through surgery or radiation treatments. Your thyroid gland produces two hormones: Triiodothyronine (T3) and Thyroxine (T4) the two hormones are released from your thyroid gland and into the blood stream. They play an important role in controlling the rate of metabolism. This is the chemical reactions that take place in your body. The amount of the hormones T3 and T4 that your thyroid gland produces, is controlled by the pituitary gland, which is in your brain. Your Pituitary gland produces a hormone called: Thyroid Stimulating Hormone (TSH) also known as Thyrotropin. TSH stimulates the thyroid gland to produce the thyroid hormones. Hypothyroidism (pronounced: hi-po-thigh-roy-dih-zum). Hypothyroidism is caused by a nonexistent or underactive thyroid gland, and it results from a developmental problem or a destructive disease of the thyroid. The thyroid releases too little of the hormone thyroxine, so a person's basal metabolic rate (BMR) is low. Not getting treatment for hypothyroidism can lead to brain and growth problems. Hypothyroidism slows body processes and causes fatigue, slow heart rate, excessive weight gain, and constipation. Teens with this condition can be treated with oral thyroid hormone to achieve normal levels in the body. Metabolism is a complex biochemical process by which the food we eat is converted into the energy in order for your body to function. (BMR) stands for Basal Metabolic Rate, and is synonymous with Basal Energy Expenditure or (BEE). BMR measurements are typically taken in a darkened room upon waking after 8 hours of sleep; 12 hours of fasting to ensure that the digestive system is inactive; and with the subject resting in a reclining position (RMR) stands for Resting Metabolic Rate, and is synonymous with Resting Energy Expenditure or (REE). RMR measurements are typically taken under less restricted conditions than BMR, and do not require that the subject spend the night sleeping in the test facility prior to testing.



When your age goes up, your BMR and RMR go down. When your height goes down, your BMR and RMR go down.

When your weight goes down, your BMR and RMR go down. This means that as you get older, shorter, and lose weight, your BMR and RMR will go down and you will need to eat less or exercise more to maintain your current weight.



BMR and RMR represent the minimum amount of energy required to keep your body functioning. You don’t gain weight because of a slow metabolism, it’s the extra calories you eat that puts on the weight.