Melatonin and valerian root, two dietary supplements, are natural sleep aids you can purchase over the counter. Most people can safely take melatonin or valerian root to help improve their sleep patterns.

Dehydroepiandrosterone, DHEA, is the most prevalent steroid in the body. It plays an important role in immunity, healing and growth. As a prohormone, DHEA increases more basic hormones such as testosterone, progesterone and estrogen. Pathology and age can reduce circulating levels of DHEA.

According to the Centers for Disease Control and Prevention, American society is increasingly characterized by the promotion of an increased intake of unhealthy foods and a lack of physical activity. This environment has led to a growing obesity problem.

There are 27 bones in the hand and wrist, and these moving parts are joined by tendons and ligaments in the normal functioning of this body part. Because many of these bones and other moving parts are interrelated, it can sometimes be difficult to identify the location of the damage.

Physiology encompasses the tissue, organ and cellular functions of the human body. An optimally healthy body has normal physiology. Conversely, human disease represents an aberration in normal physiology--something in the body fails to function as it should.

One minute, your 18-month-old may be happily playing, and the next, she might be flailing on the floor in the grips of a temper tantrum. You may wonder what happened to your sweet baby, and whether you are entering the territory of the Terrible Twos, albeit a few months early.

A 3.5-ounce serving of venison steak -- or 100 grams -- contains 18 milligrams of dietary cholesterol. That is less than the cholesterol in most other meats, both red and white.

Shaolin kung fu is a type of martial arts associated with the Shaolin monasteries in China. The philosophy of Shaolin is a combination of Taoism and Buddhism. Meditation is an essential part of the Shaolin martial art practice, allowing you to banish negative thoughts and gain strength from your mind.

For centuries, the way blood circulated seemed more magic than science, until 1628 when William Harvey described the mechanics by which it flowed against the force of gravity, in his work "De Motu Cordis." Your cardiovascular system pumps and delivers crucial oxygen and nutrients to your entire body.

Also known as heart palpitations, an irregular heartbeat associated with exercising usually manifests as an unnatural fluttering, skipping or pounding of the heart. It is often conspicuous enough to to detect without using a heart monitor or checking pulse.

Rosmarinus officinalis is an evergreen shrub native to the Mediterranean region and is commonly used as a spice in a number of ethnic cuisines. With its pungent aroma, rosemary has been used as a flavoring agent as well as for its medicinal qualities for hundreds – if not thousands – of years.

Infrared rays are invisible waves of energy that penetrate deep into the inner tissues, muscles and bones of the body, reports the Online Global Healing Center. The energy from these waves slightly elevates the surface temperature of your body.