STIs can have significant impacts on reproductive health if left untreated. Some potential consequences include: - Chronic Pain: Conditions like pelvic inflammatory disease (PID) can cause ongoing pain. - Infertility: Certain STIs, such as chlamydia and gonorrhea, can lead to infertility if not treated promptly. - Cancer: Human papillomavirus (HPV) is linked to cervical and other types of cancers.