Menopause is a widely known occurrence in women where women no longer produce sex hormones, including estrogen and progesterone. While the condition is often lesser-known, men do go through a reduction in sex hormone production known as andropause. The name refers to the decline in androgens or male sex hormones. The hormone testosterone is the primary sex hormone that declines in andropause although other hormones do reduce as well. Andropause can cause a man’s hormone levels to decrease anywhere from 1 to 2 percent per year, beginning after age 30. This is why an estimated 40 percent of men in the United States have low testosterone levels by the age of 40. While women’s hormone levels drop quickly, the gradual slowing of men’s sex hormones can cause effects for decades before a man may link his symptoms to those of hormonal decline. By this time, they have lost many years of their lives feeling tired, depressed, or experiencing difficulty thinking needlessly. Decreases in male sex hormones are not the only hormones that may decrease over time. Aging can cause reductions in hormones, such as those of the thyroid, adrenal glands, growth hormones and vitamin D deficiency.