1. When combined with exercise, a healthy diet can help you lose weight, lower your cholesterol level and improve the way your body functions on a daily basis.

  2. Sexually transmitted diseases (STDs) are infections you can get by having sex with someone who has an infection. These infections are usually passed by having intercourse, but they can also be passed through other types of sex. STDs can be caused by viruses or bacteria. STDs caused by viruses include hepatitis B, herpes, HIV and the human papilloma virus (HPV). STDs caused by bacteria include chlamydia, gonorrhea and syphilis.

  3. If you've ever had sex, you may be at risk for having an STD. Your risk is higher if you have had many sex partners, have had sex with someone who has had many partners or have had sex without using condoms.

  4. Smoking causes changes in your body and in the way you act. The changes in your body are caused by an addiction to nicotine. The changes in the way you act developed over time as you bought cigarettes, lit them and smoked them. These changes have become your smoking habit.

  5. Insomnia is the body's way of saying that something isn't right. Things that may cause insomnia include stress, too much caffeine, depression, changes in work shifts, and pain from medical problems.

  6. One way to prevent tooth decay and periodontal (gum) disease is by eating a balanced diet and limiting the number of between-meal snacks. If you need a snack, choose nutritious foods such as raw vegetables, plain yogurt, cheese or a piece of fruit.