Hormones function as messengers in the body. Sex hormones are produced primarily by the adrenal glands and ovaries in women where they travel by way of the bloodstream to specific target organs delivering their message. Sex hormones must be in optimal concentration and proper relationship to one another to function at their best. Hormones each have their checks and balances. Each hormone in the body has a counterpart that regulates its function. When one is either excessive or deficient, the normal ratio is disturbed and the optimal function of the hormone is altered. This disturbance in hormone balance can affect many body systems leading to weight gain, fatigue, irregular menses, hot flushes, infertility, decreased sex drive, moodiness, irritability, and sleep disturbances. These are common premenopausal symptoms that women can experience long before the onset of menopause.