Early identification of STIs is not always possible. For example, chlamydia and gonorrhea often have no noticeable signs or symptoms in women. However, early identification, if possible, is important both to avoid passing on the infection and to avoid serious long-term health consequences, such as stillbirth, cervical cancer, and congenital syphilis. To help detect STIs early, a provider can:

  • Ask the client’s sexual history and assess the risk of having an STI
  • Ask whether the client or the client’s partner has genital sores or unusual discharge
  • Look for signs of STIs when doing a pelvic or genital examination for another reason
  • Know how to advise a client who may have an STI
  • Promptly diagnose and treat, or else refer for appropriate care, the client who has signs or symptoms
  • Advise clients to notice genital sores, warts, or unusual discharge in themselves or in their sexual partners
  • For clients without STI signs or symptoms but who are at high risk for STIs, encourage syphilis screening and, when feasible, screening for gonorrhea and chlamydial infection

Common signs and symptoms that may suggest an STI include:

Symptoms Possible cause
Discharge from the penis—pus, clear or yellow-green drip Commonly: Chlamydia, gonorrhea

Sometimes: Trichomoniasis

Abnormal vaginal discharge or
pain during sex
Chlamydia, gonorrhea, pelvic inflammatory disease
Burning or pain during urination Chlamydia, gonorrhea, herpes
Lower abdominal pain or pain during sex Chlamydia, gonorrhea, pelvic inflammatory disease
Swollen and/or painful testicles Chlamydia, gonorrhea
Itching or tingling in the genital area Commonly: Trichomoniasis

Sometimes: Herpes

Blisters or sores on the genitals, anus, surrounding areas, or mouth Herpes, syphilis, chancroid
Warts on the genitals, anus, or surrounding areas Human papillomavirus
Unusual vaginal discharge—changes from normal vaginal discharge in color, consistency, amount, and/or odor Most commonly: Bacterial vaginosis, candidiasis (not STIs; see Common Vaginal Infections Often Confused With Sexually Transmitted Infections)

Commonly: Trichomoniasis

Sometimes: Chlamydia, gonorrhea