Anorexia Nervosa is an eating disorder in which a person limits eating, and weighs at least 15 percent less than her ideal weight. It usually is considered a female disorder because at least 90 percent of cases are in young women, but it can occur in men or in older people.

A person with this disorder fears being fat, and may be completely convinced that she is overweight despite what the scale shows or what other people say. To achieve or maintain leanness, she may exercise obsessively or use laxatives. Since a super-restrictive diet requires exquisite control, she may become quite careful, inhibited and controlled in other areas of life. For example, she may retreat from social contacts or may perform ritual behaviors.

Osteoporosis is a bone disorder. The bones become thinner, lose their strength and are more likely to break. People with osteoporosis have a higher risk of fractures. Their bones can fracture even during everyday movements, such as bending or coughing. Osteoporosis is not a form of arthritis, although it can cause fractures that lead to arthritis.

In the United States, osteoporosis causes more than 1.3 million fractures each year. It is much more common in women than in men because of the hormonal changes that occur during menopause. In people with osteoporosis, the wrist usually is fractured first. This typically occurs between ages 50 and 70 in women. However, hip fractures and fractures of the spine are even more common, especially among people in their 70s.