Medical science and the unraveling of the human genome have, and are, providing us with great insights into how our bodies work and how we are susceptible to diseases and the aging process. Our new understandings now allow us to significantly increase our healthy longevity. And when we take advantages of these new findings we make ourselves available to take advantages of the even newer technologies being developed. There are seven basic causes that combine to make us vulnerable to diseases and to aging; they are all described in the book Aging is a Treatable Disease. One of the major causes is that our endocrine system ceases to secrete sufficient quantities of certain enzymes and hormones to keep up with the cell's battles with the build up of contaminants. The purpose of this book is to describe this major problem caused by the decline of our hormones with age and to describe what we can do about it. Our hormones regulate and control most of the functions of our bodies. Testosterone and estrogen, the major sex hormones in men and women respectively, give us the urge and ability to reproduce and continue the survival of our species. But once we're past our reproductive prime, our hormone levels drop. This results in a lack of sex drive, insomnia, impotence, weight gain, and countless other potential health problems that significantly decreases our quality of your life. So we see that our hormone system was designed primarily for reproduction for the survival of the species. Our bodies produce high quantities of certain hormones and enzymes during our youth. These give us our youthful vitality, strength, and endurance. They help in the battles against free radicals and they help provide nutrients for cell repair. They keep our cells cleansed of the ashes of metabolism and environmental toxins. As long as our bodies produce sufficient quantities of these enzymes and hormones, we stay young. But we, and all plants and animals were designed to stay healthy until we have reproduced and reared our young. Mother Nature has little interest in us after we have passed our genes on to the next generation. As we age past our prime reproductive years we are no longer capable of producing sufficient quantities of the enzymes and hormones required to keep our cells "young and fit." With too little of these substances, our cells begin to lose their battles against the free radicals and other destructive elements. The cells begin to age, and die. The organs of which they are a part become ineffective. We become frail, we die. But we can now do something about our hormones. To make sure you are around when new health discoveries are proven and available, you need to under your hormones and what they do for you and what you can do to keep them functioning.