Basal metabolism is usually expressed in terms of basal metabolic rate, which is between 1,200 and 1,300 kcal in a normal adult female, and is affected by factors such as age and gender. Basal metabolism is the minimum energy requirement for all organs of the body to sustain life. It is usually expressed in terms of basal metabolic rate, which is not affected by the environment, temperature, muscle activity, etc., but is affected by factors such as height, body weight, age and sex. Usually men have a higher basal metabolic rate than women, and older basal metabolic rates are lower than younger basal metabolic rates. A normal basal metabolism for an adult female is around 1200-1300kcal a day. The common formula for basal metabolic rate is (pulse rate + pulse pressure) – 111, which is considered normal if it does not exceed or fall below 15% of the normal value. The basal metabolic rate is a major aid in the clinical diagnosis of thyroid disorders. It may be significantly higher in hyperthyroidism and lower in hypothyroidism. It is recommended to seek prompt medical attention if an abnormal basal metabolic rate occurs.