The most common causes of yellow vaginal discharge are various vaginal infections, primarily bacterial vaginosis (BV) and trichomoniasis. Some sexually transmitted diseases, including gonorrhea and chlamydia, may also lead to yellowish vaginal discharge. More rarely, an infection in the vagina due to an intrauterine device may lead to discharge which resembles pus.
Bacterial vaginosis (BV) is the most common cause of yellowish vaginal discharge. It is an infection which occurs when normal bacteria in the vagina grow more rapidly than usual and outnumber the "good" bacteria. Additional symptoms may include itching, inflammation, tenderness, burning, and a foul odor. This condition is generally easily treated with prescription antibiotics. Although it is most common in women who are sexually active, BV is not a sexually transmitted disease.
Another potential cause of vaginal discharge with a yellow color is trichomoniasis. This is a small parasitic organism which can potentially infect the vagina, digestive tract, and urinary tract. Symptoms of the vaginal version may include a yellow or green vaginal discharge which may be foamy in nature. A foul odor is also common, as well as irritation and pain upon urination if the infection spreads into the urinary tract. It is a sexually transmitted condition, although it is usually easily treated.
Both chlamydia and gonorrhea are sexually transmitted diseases which may cause yellow vaginal discharge in some patients. Other symptoms can include irritation and redness around the genitals, pain when urinating, and sometimes lower abdominal pain. Both conditions can be treated when caught early, but when left untreated they may lead to serious damage within the reproductive tract.
Women may prevent most of these conditions by practicing safe sex and following proper hygiene practices. Wiping should be done from front to back to avoid getting fecal matter into the vagina. It is also a good idea to wear white cotton underwear, to avoid using perfumed soaps and douches, and to clean towels and undergarments after each use. Any unusual symptoms should be reported to a health care professional for proper treatment.
When testing to find the cause of yellow vaginal discharge a doctor will generally take a swab and collect samples of the discharge from the vagina. Sometimes additional swabs are taken from the cervix directly. Numerous samples may be taken if more than one infection is suspected. These samples are then sent to a lab for testing for each of the potential causes. Many times patients will be treated with a powerful broad spectrum antibiotic in order as a precaution in case symptoms are being caused by a more serious infection.