This Stain on Your Underwear

Not every mark on your underwear is a sign of a health problem. Vaginal discharge naturally changes throughout the menstrual cycle, and normal discharge can range from clear and watery to white or slightly cloudy.

However, a noticeable change in color, odor, amount or consistency—especially when accompanied by other symptoms—may deserve attention. The appearance alone cannot determine the cause, and medical testing may be needed to identify an infection.

A thick, clumpy white discharge accompanied by significant itching, irritation or burning can occur with vaginal yeast infections.

The symptoms are more important than the stain itself. If the discharge is repeatedly abnormal or symptoms are uncomfortable, it is better to get evaluated rather than assuming it is a yeast infection and self-treating.

Bacterial vaginosis (BV) can cause thin white or gray discharge and may produce a strong, fish-like odor, particularly after sex. Some women have few or no symptoms.

BV is caused by an imbalance of bacteria in the vagina and can be diagnosed by a healthcare professional.

A yellow or green discharge—particularly when accompanied by an unpleasant odor, irritation, pelvic discomfort or pain when urinating—can be associated with an infection.

Some sexually transmitted infections, including trichomoniasis or chlamydia, can cause abnormal discharge. Importantly, some STIs may produce few or no symptoms, so appearance alone cannot tell you what is happening.

A small amount of spotting can have many causes, including menstruation, hormonal changes or irritation.

But unexplained vaginal bleeding, bleeding between periods or bleeding after menopause should not simply be dismissed. Persistent abnormal bleeding should be evaluated by a healthcare professional.

Pay attention if a change in discharge is accompanied by:

The CDC notes that symptoms alone are often not enough to accurately determine the cause of vaginal discharge. Examination and laboratory testing may be necessary.

A photo or stain on underwear cannot reliably tell you whether you have a yeast infection, BV, an STI or another condition.

Even when the discharge looks unusual, there can be several possible explanations. Using the wrong over-the-counter treatment may delay the correct diagnosis.

An unusual stain doesn’t automatically mean something is seriously wrong. Vaginal discharge naturally changes throughout the menstrual cycle.

But if the discharge suddenly changes in color, consistency, amount or smell, particularly when other symptoms appear, it’s worth getting checked.

Your underwear may provide a clue—but only a proper medical evaluation can determine the cause.