A vaginal disease is a pathological condition that affects part or all of the vagina. A vaginal disease is a pathological condition that affects part or all of the vagina. Sexually transmitted disease that affect the vagina include: HIV/AIDS can be contracted through the vagina during vaginal intercourse, but it is not associated with any local vaginal or vulval disease. Because of STIs, health authorities and other health outlets recommend safe sex practices when engaging in sexual activity. Vaginismus, which is not the same thing as vaginitis (an inflammation of the vagina), is an involuntary tightening of the vagina due to a conditioned reflex of the muscles in the area during vaginal penetration. It can affect any form of vaginal penetration, including sexual intercourse, insertion of tampons and menstrual cups, and the penetration involved in gynecological examinations. Various psychological and physical treatments are possible to help alleviate it. A vaginal obstruction is often caused by an imperforate hymen or, less commonly, a transverse vaginal septum. A sign of vaginal obstruction is hydrocolpos, that is, accumulation of watery fluid within the vagina. It may extend to become hydrometrocolpos, that is, accumulation of watery fluid within the vagina as well as within the uterus. Vaginal hypoplasia is the underdevelopment or incomplete development of the vagina. Vaginal hypoplasia can vary in severity from being smaller than normal to being completely absent. The absence of a vagina is a result of vaginal agenesis. Diagnostically, it may look similar to a vaginal obstruction. It is frequently associated with Mayer-Rokitansky-Küstner-Hauser (MRKH) syndrome, in which the most common result is an absent uterus in conjunction with a deformed or missing vagina, despite the presence of normal ovaries and normal external genitalia. It is also associated with cervical agenesis, in which the uterus is present but the uterine cervix is absent. The presence of unusual lumps in the wall or base of the vagina is always abnormal. The most common of these is Bartholin's cyst. The cyst, which can feel like a pea, is formed by a blockage in glands which normally supply the opening of the vagina. This condition is easily treated with minor surgery or silver nitrate. Other less common causes of small lumps or vesicles are herpes simplex. They are usually multiple and very painful with a clear fluid leaving a crust. They may be associated with generalized swelling and are very tender. Lumps associated with cancer of the vaginal wall are very rare and the average age of onset is seventy years. The most common form is squamous cell carcinoma, then cancer of the glands or adenocarcinoma and finally, and even more rarely, vaginal melanoma. Persistent genital arousal disorder (PGAD), which results in a spontaneous, persistent, and uncontrollable genital arousal, with or without orgasm, unrelated to any feelings of sexual desire. Because PGAD is relatively rare and, as its own concept apart from clitoral priapism (a rare, potentially painful medical condition in which, for an unusually extended period of time, the erect clitoris does not return to its relaxed state), has only been researched since 2001, there is little research into what may cure or remedy the disorder. In some recorded cases, PGAD was caused by, or caused, a pelvic arterial-venous malformation with arterial branches to the clitoris; surgical treatment was effective in these cases.