Foreskin: The loose skin that covers the head of the penis.
Frotteurism: A disorder in which the focus of a person's sexual urges is related to touching or rubbing their genitals against the body of a non-consenting, unfamiliar person.
Gender: Being male or female.
Gender identity disorder: A disorder in which a male or female feels a strong identification with the opposite sex.
Genital warts (condyloma): Growths or bumps on the penis, vagina, vulva (vaginal lips), cervix (the opening between the vagina and womb), rectum, or groin. Genital warts are a sexually transmitted disease (STD), which means that they are spread by having sex with an infected person.
Glans: The head of the penis.
Gonorrhea: A serious bacterial infection that is caught by having sex with an infected person. A person can become infected when the bacteria enter any opening in the body, including the penis, anus, vagina, or mouth. Gonorrhea also is called "clap" or "drip."
Hepatitis: A disease involving inflammation of the liver. Most types of hepatitis are caused by viruses, but alcohol, drugs, and other factors also can cause the disease. Hepatitis can cause long-term damage to the liver.
Hepatitis B: A type of hepatitis that can be spread from another person who has the virus. Most commonly, it is spread by having sex with an infected person or by sharing a needle.
Herpes: A virus spread by close personal contact, such as kissing or sexual intercourse. There are two types of herpes. The first type is herpes simplex type 1 (or HSV-1). HSV-1 occurs most often on or near the mouth and appears as a blister or cold sore. The second type, herpes simplex type 2 (or HSV-2), occurs most often on or near the sex organs and is sometimes called "genital herpes."
Heterosexual: A person who is attracted to individuals of the opposite gender.
HIV test: A test to look for signs of HIV in the blood.
Homosexual: A person who is attracted to individuals of the same gender.
Hormones: Chemicals that stimulate or regulate the activity of cells or organs.