What Causes Greenish Vaginal Discharge?

Greenish vaginal discharge is an abnormal finding that warrants prompt medical evaluation. Unlike normal vaginal secretions—which are typically clear, white, or off-white and odorless—green discharge often signals an underlying infection, most commonly trichomoniasis, a sexually transmitted infection caused by the protozoan *Trichomonas vaginalis*. This organism triggers inflammation of the vaginal mucosa, leading to a characteristic frothy, greenish-yellow discharge, frequently accompanied by itching, burning, dysuria, and a foul, fishy odor.

Less commonly, green discharge may arise from bacterial vaginosis (BV), particularly in cases with pronounced polymicrobial overgrowth or secondary infection. While BV classically presents with thin, grayish-white discharge and a strong amine odor, atypical presentations—including green-tinged secretions—can occur, especially when mixed infections or *Prevotella* or *Mobiluncus* species predominate.

Other potential causes include cervicitis or endometritis due to *Chlamydia trachomatis* or *Neisseria gonorrhoeae*, though these more often produce purulent yellow or white discharge. Rarely, retained foreign bodies (e.g., forgotten tampons or contraceptive devices) can lead to polymicrobial infection and greenish, malodorous discharge. In immunocompromised individuals, opportunistic pathogens such as *Pseudomonas aeruginosa* may also cause green-tinged secretions.

It is critical to avoid self-diagnosis or over-the-counter treatments, as mismanagement can delay appropriate therapy and increase risks of complications—including pelvic inflammatory disease, infertility, or adverse pregnancy outcomes. Diagnosis relies on clinical assessment, wet-mount microscopy, nucleic acid amplification testing (NAAT), and, when indicated, culture or point-of-care testing. Treatment is pathogen-specific: metronidazole or tinidazole for trichomoniasis; topical or oral antibiotics for BV; and dual therapy (ceftriaxone plus azithromycin or doxycycline) for gonorrhea and chlamydia.

Patients experiencing green vaginal discharge should seek evaluation by a healthcare provider without delay. Sexual partners must also be assessed and treated when appropriate to prevent reinfection and further transmission.