One of the most frequently experienced medical symptoms of girls and women is abnormal vaginal discharge. It can be pretty scary if you don’t know what is causing it. Below is a list of the major causes of vaginal discharge along with the specific characteristics of the discharge that can help distinguish it from other causes.

There can also be an increase in the amount of vaginal discharge that is perfectly normal. Normal vaginal discharge is usually clear or milky and doesn't smell bad. Possible causes for an increase in the amount of normal vaginal discharge include emotional stress, ovulation, breastfeeding, and sexual excitement.

The Top 10 causes of abnormal vaginal discharge are:

• Bacterial vaginosis (BV)
  The most common cause of abnormal vaginal discharge, BV occurs when bacteria that normally live in the vagina overgrow, causing a grey discharge and fishy odor that tend to worsen after sexual intercourse. You may also experience itching or burning and a slight redness and swelling of the vagina or vulva. BV is not sexually transmitted and can be treated with antibiotics.
  
  
• Vaginal yeast infection
  Yeast is a fungus that can normally be found in very small amounts in a healthy vagina. If the yeast overgrows, it can cause a yeast infection, which is the second most common cause of abnormal vaginal discharge. Yeast infections may cause a white, cottage cheese-like discharge along with an intense itching sensation, although not everyone with a yeast infection will have the discharge. There may also be swelling around the vulva and sexual intercourse is often painful. The discharge associated with a yeast infection does not usually smell bad; at worst it may smell faintly starchy. Yeast infections are more common in women using antibiotics, who are pregnant, have diabetes, or stay hot and sweaty for long periods. Yeast infections can be treated with antifungal medication medicine you put into your vagina, or with oral medicine.
  
  
• Trichomoniasis
  Trichomoniasis is an infection caused by the bacterium Trichomonas vaginalis. It causes copious, thin, bubbly discharge that is yellowish or greenish in color. It is usually associated with an unpleasant odor and pain and itching during urination. Trichomoniasis is often most apparent after your period. You can be infected but have no signs for a long time. Trichomoniasis is usually contracted through unprotected sex with someone who is infected. It can be treated with oral antibiotics.
  
  
• Chlamydia
  Chlamydia is the most common sexually transmitted disease (STD) in the United States and is caused by the bacterium, Chlamydia trachomatis. Chlamydia often causes no symptoms, but if untreated, may cause damage to the reproductive organs. The vaginal discharge sometimes associated with Chlamydia is milky or yellow and mucus-like with a mild but unpleasant odor. Other symptoms may include painful urination, lower abdominal pain, and painful sexual intercourse. Chlamydia is easily treatable with antibiotics.
  
  
• Gonorrhea
  Gonorrhea is a sexually transmitted disease (STD) caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in the warm, moist areas of the female reproductive tract. Most women who are infected have no symptoms. If symptoms do occur, they may include a cloudy, yellow or green, pus-like vaginal discharge along with a burning sensation when urinating, persistent lower abdominal pain, and spotting between periods. Complications of untreated gonorrhea include pelvic inflammatory disease and sterility. Most cases of gonorrhea can be treated with common oral antibiotics.
  
  
• Genital herpes
  A recurrent outbreak of genital herpes (i.e. not the very first herpes outbreak you experience) may be accompanied by a watery vaginal discharge. Sometimes herpes sores may not be visible in women, so a change in discharge may be the only clue. Often it will be accompanied by itching and burning, pain when urinating, and the presence of oozing blisters.
  
  
• Forgotten tampon or foreign body
  If a foreign body is left in the vagina, it will cause a foul-smelling black discharge. This can become dangerous if the infection spreads to the body or blood causing toxic shock syndrome or sepsis.
  
  
• Infected IUD
  An infected intrauterine device (IUD) may cause a pus-like cervical discharge along with mild uterine tenderness. Removal of the device should stop the discharge and the pain.
  
  
• Atrophic vaginitis
  After menopause, levels of estrogen change dramatically and this can cause changes in vaginal tissues called atrophic vaginitis. A thin, watery discharge, sometimes blood-tinged, may sometimes occur, along with inflammation of the vagina and thinning and shrinking of the vaginal tissues. It only occurs in women who are post-menopausal or whose ovaries have been surgically removed. Symptoms may be aleviated with the use of topical estrogen creams.
  
  
• Cervical or vaginal cancer
  Cancers of the lower reproductive tract in women may rarely be the cause of excess vaginal discharge. Early symptoms of cancer may include a continuous vaginal discharge, which may be pale, watery, pink, brown, bloody, or foul-smelling.

For more information about sexually transmitted diseases in women or about women's health, join the Healia Health Community for STDs or the Healia Health Community for Women's Health. To learn more, read the Healia Health Guide to Chlamydia or the Healia Health Guide to Genital Herpes.

<sub>Sources: National Library of Medicine, MedlinePlus Medical Encylopedia, Vaginal Discharge, Updated 8/07. http://www.nlm.nih.gov/medlineplus/ency/article/001345.htm
American Academy of Family Physicians, Vaginal Dischage: Changes That may be Signs of a Problem, Updated 1/08. http://familydoctor.org/online/famdocen/home/women/reproductive/vaginal/194.html

Photo: d'n'c, Flickr, Creative Commons</sub>