What Types of STDs Cause Abdominal Pain?

Lower-abdominal or pelvic pain from a sexually transmitted infection most often points to pelvic inflammatory disease (PID), a complication of untreated chlamydia or gonorrhea. Chlamydia and gonorrhea themselves can ache as they spread upward. But ovarian cysts, endometriosis, and urinary infections cause the same pain, and only a test sorts them out.

Which STIs cause lower-abdominal or pelvic pain?

The pain you feel in your lower belly or pelvis usually isn't the infection sitting quietly on the cervix. It's the infection moving up into the deeper reproductive organs and inflaming them, the common thread linking the STI causes below. Each one has a tell-tale pattern, but the patterns overlap enough that the symptom alone can't name the culprit.

Pelvic inflammatory disease (PID)

PID is an infection of the upper female reproductive organs, the uterus, fallopian tubes, and ovaries, most often a complication of an untreated lower-tract STI, especially chlamydia and gonorrhea, that has climbed upward CDC. As the tubes and ovaries inflame, the classic picture is lower-abdominal or pelvic pain, unusual discharge with a bad odor, fever, pain or bleeding during sex, burning when you urinate, and bleeding between periods. Symptoms are often mild or absent, so many people don't realize anything is wrong until scarring has already started.

Because that scarring in the fallopian tubes can lead to infertility, ectopic pregnancy (a pregnancy that implants outside the uterus, which is dangerous), and chronic pelvic pain, clinicians treat PID aggressively. CDC advises a low threshold to start treatment: presumptive therapy is recommended for pelvic or lower-abdominal pain with no other identifiable cause plus at least one of cervical-motion tenderness, uterine tenderness, or adnexal tenderness on exam CDC, 2021. There's no single confirmatory test, so this is a clinical diagnosis and your provider treats on the picture rather than waiting for a lab to prove it.

If you're diagnosed with PID, your sexual partners almost always need treatment too, even if they feel fine, or they'll re-infect you. We walk through that question here: PID partner treatment

Chlamydia

Chlamydia is caused by the bacterium Chlamydia trachomatis, and most US genital infections come from the D. K serovars CDC. It's the original 'silent' infection: roughly three quarters of infected women and half of infected men have no symptoms at all, so it goes unnoticed long enough to climb. When women do have symptoms, the early ones are abnormal vaginal discharge and burning on urination. If the infection spreads upward, you get lower-abdominal or low-back pain, fever, pain during intercourse, and bleeding between periods. That spread is essentially early PID.

Timing helps a little: when symptoms appear, they usually show up within one to three weeks after exposure. So new pelvic pain a couple of weeks after a new partner is a reasonable reason to test for chlamydia. But because most cases are quiet, a stretch without symptoms doesn't mean you're clear.

Gonorrhea

Gonorrhea is caused by Neisseria gonorrhoeae, which can infect the genitals, rectum, and throat CDC. In men, it tends to announce itself with burning on urination and a white, yellow, or green penile discharge; less commonly it causes swollen, painful testicles (epididymitis, inflammation of the tube behind the testicle that can affect fertility). In women, most have no symptoms, but when they appear they're painful or burning urination, increased vaginal discharge, and bleeding between periods. Like chlamydia, an untreated cervical gonorrhea infection can ascend and trigger PID, which is where the deeper pelvic pain comes from.

Pelvic pain plus discharge after a new exposure is enough reason to get checked for gonorrhea. Co-testing with chlamydia is standard since the two travel together.

When it's NOT an STI

Plenty of lower-abdominal and pelvic pain has nothing to do with an infection you caught from a partner. The common non-STI culprits include:

• Ovarian cysts: fluid-filled sacs on the ovary that can cause sharp, one-sided pain, especially around ovulation or if one ruptures.
• Endometriosis: tissue similar to the uterine lining growing outside the uterus, which causes cyclical, often severe pelvic pain tied to your period.
• Urinary tract infections: a bladder or kidney infection that brings burning urination, pelvic pressure, and sometimes fever, mimicking an STI but driven by ordinary gut bacteria.

These can feel exactly like an early STI, which is why self-diagnosing pelvic pain is so unreliable.

How to tell them apart

You mostly can't tell them apart by feel. These conditions overlap too much to separate by sight alone, and several are frequently silent. A few patterns nudge the odds: pain that's strictly cyclical with your period leans toward endometriosis; sudden sharp one-sided pain mid-cycle suggests an ovarian cyst; burning urination with cloudy urine and no new partner points at a UTI; and pain with odorous discharge, fever, and a recent new partner raises suspicion for PID from chlamydia or gonorrhea. A test turns a guess into an answer.

How it's tested

For chlamydia and gonorrhea, a nucleic acid amplification test (NAAT) is the recommended method, run on a urine sample or a self-collected swab; for gonorrhea its sensitivity is usually above ninety percent with specificity around ninety-nine percent CDC. PID is diagnosed on the exam rather than a single lab. In practice testing means a urine cup, a swab, or a quick pelvic exam depending on what's suspected, and it's free or low-cost at health departments, Planned Parenthood, and Title X clinics, with results usually back in a few days. Start here: get tested.

Timing matters too. Test too soon after an exposure and a real infection can read negative. See when to test after exposure before you book.

What to do next

If you have new pelvic pain, get evaluated rather than waiting it out. Chlamydia and gonorrhea are curable with antibiotics, and treating them early prevents the tubal scarring that causes infertility CDC, 2021. PID is treated presumptively the moment the exam supports it, often without waiting for results. Don't have sex until you and your partner have finished treatment, and make sure partners are notified so they don't re-infect you.

Red flags, when to get seen urgently

Some pelvic pain can't wait for a routine appointment. Seek same-day or emergency care if you have:

• Severe or rapidly worsening lower-abdominal pain, especially with fever and chills.
• Pain with a fever and foul-smelling discharge, a picture suggesting active PID.
• Sudden sharp one-sided pain with faintness or shoulder-tip pain, which can signal an ectopic pregnancy or a ruptured cyst.
• Pain plus vomiting that keeps you from holding down fluids or oral antibiotics.
• Any severe pelvic pain during a known or possible pregnancy.

Keep exploring on EasySTD: compare testing services, STD incubation periods and Chlamydia testing.