Rough, dark patches of skin on the knees are not unusual. Your knees bear the brunt of many physical activities. Children learning to crawl are very hard on their knees, as are the parents who kneel on the floor to interact with them at eye level. Generally speaking, rough patches of skin indicate dryness.

Periodontal disease is a chronic infection of bacteria around the teeth. Mild forms of the condition are gingivitis, with more severe forms known as periodontitis. The condition affects the gums, underlying bones of a tooth and the tooth itself.

A kitchen burn from steam, hot liquids or direct contact with the burner or pot may be mild or severe. A first-degree burn does not blister the skin, according to University of Utah's Hospital Burn Center. Second-degree burns blister, while third-degree burns blister and burn all the way down to the muscles and bone.

Approximately 3 million teenagers wear braces, according to research by toothpaste manufacturer Colgate. These orthodontic devices are used to correct tooth and jaw alignment, including overbites, underbites, crossbites and crowding. Metal brackets connected to a wire are mounted to the rear molars.

Breast implants are not usually covered by insurance companies, notes the American Society of Plastic Surgeons. This makes you responsible for the costs incurred from the surgery, including facility costs, anesthesia fees and the cost for the actual implants.

Popcorn has several effects in your body; some good, some unpleasant. Enjoying a serving of popcorn here and there counts towards your daily recommended servings of grain foods, which is 3 to 4 oz. or equivalents, says MyPlate.gov. Since popcorn bulks up when you expose it to heat, a 1 oz.

Female condoms have many benefits. They are effective against sexually transmitted infections and pregnancy. Perhaps the best benefit of the female condom is that it's a female-controlled device that doesn't rely on prescription medications to prevent pregnancy.

Donating blood is often described as giving the gift of life. While you may lose a little weight and burn some calories during a donation, giving blood should not be thought of as a weight loss tool. Think of it as a chance to help others in need.

Cayenne pepper belongs to the chili pepper family and contains the compound capsaicin, which is responsible for its burning heat as well as its health benefits, according to the University of Maryland Medical Center. Besides being a great source of vitamin A, cayenne pepper also has anti-inflammatory properties.

Laser prostate surgery involves the use of concentrated, high-energy waves and intense heat to destroy prostate gland tissue that obstructs the flow of urine or causes other complications.

Thrush--also called a yeast infection or Candidiasis--is caused by the Candida albicans micro-organism growing out of control. Symptoms include white patches in the mouth, a cottony feeling in the mouth, and an inability to taste. Thrush is more common in babies, older adults, and people with weakened immune systems.

Around 58 percent of Americans experience insomnia-like symptoms each week, reports the National Sleep Foundation. These symptoms include waking without feeling refreshed, having trouble staying asleep and not being able to fall asleep quickly.