Most STIs either feel like nothing at all or produce a handful of recognizable sensations: burning when you pee, unusual discharge, sores on or around the genitals, or a dull ache deep in the pelvis. The tricky part is that an estimated 77% of chlamydia cases and 45% of gonorrhea cases never produce symptoms. So “what does it feel like” is genuinely complicated, because the most common answer for many infections is “you wouldn’t know.”
That said, when symptoms do show up, each infection has a somewhat distinct signature. Here’s what to actually expect, broken down by sensation.
Burning During Urination
A stinging or burning feeling when you pee is one of the most common early signs of chlamydia, gonorrhea, and trichomoniasis. It can range from mild irritation to a sharp sting that makes you dread going to the bathroom. This is also the symptom most easily confused with a urinary tract infection, since UTIs cause the same burning sensation along with frequent urges to pee.
The key difference: STIs typically come with abnormal discharge from the vagina or penis, while UTIs usually don’t. UTIs also tend to make you feel like you need to pee constantly, even when your bladder is nearly empty. If you have burning plus discharge, itching, or sores, an STI is more likely. If it’s burning plus frequent urination and cloudy pee but no discharge, a UTI is the more common culprit. Either way, both need treatment, and testing can sort it out quickly.
Unusual Discharge
Discharge is one of the more noticeable and unsettling symptoms. What it looks like depends on the infection:
- Trichomoniasis produces thin, frothy, or bubbly discharge that’s yellow, green, or gray, often with a strong fishy odor.
- Chlamydia causes white or yellow discharge with a foul smell.
- Gonorrhea typically produces green or yellow discharge.
In people with penises, discharge from gonorrhea or chlamydia often appears at the tip of the penis, sometimes only in the morning. It can be thick or watery. In people with vaginas, changes in discharge can be harder to distinguish from normal variation, which is part of why these infections go unnoticed so often.
Sores, Blisters, and Bumps
Genital sores are the hallmark of herpes and syphilis, but they feel very different from each other. Herpes typically appears as clusters of small, painful blisters that break open into shallow ulcers. The first outbreak is usually the worst and can come with a tingling or burning sensation in the skin before the blisters even appear. The area feels raw, and clothing or friction can make it significantly more uncomfortable. Herpes blisters tend to show up within 2 to 12 days after exposure, with an average of about 4 days.
Syphilis, by contrast, starts with a chancre: a single, firm, round sore that is typically painless. Because it doesn’t hurt, people often miss it entirely, especially if it appears inside the vagina, on the cervix, or in the rectum. The chancre shows up anywhere from 10 to 90 days after exposure, with 21 days being average. It heals on its own after a few weeks, which can create a false sense that everything is fine, even though the infection is progressing.
HPV can cause genital or anal warts, which are flesh-colored bumps that are usually painless but may itch. These can take weeks to many months to appear.
Pelvic and Abdominal Pain
Deep, aching pain in the lower abdomen or pelvis is a sign that an infection has moved beyond the surface. In people with vaginas, untreated chlamydia or gonorrhea can travel into the uterus and fallopian tubes, causing pelvic inflammatory disease. PID pain is often subtle or vague at first. It can feel like a dull, constant ache low in the belly, sometimes worsening during sex or around your period. Some people also experience heavier or more painful periods, or bleeding between cycles.
PID symptoms vary widely, and many cases are mild enough that people push through without realizing something is wrong. That’s what makes it dangerous: the inflammation can cause lasting damage to reproductive organs even when the pain isn’t severe.
In people with penises, gonorrhea and chlamydia can cause swelling and pain in one or both testicles. This can feel like a tender, heavy ache, sometimes with visible swelling.
Flu-Like Symptoms
Some STIs trigger whole-body symptoms that feel nothing like a genital infection. Acute HIV infection, which develops within 2 to 4 weeks after exposure, can cause fever, headache, body aches, and a rash. It feels a lot like the flu or a bad cold, which is why most people don’t connect it to a sexual exposure. These symptoms typically fade on their own, and the virus then enters a long period where it causes no noticeable symptoms at all, sometimes lasting years.
Syphilis in its secondary stage (weeks to months after the initial chancre heals) can also cause fever, fatigue, sore throat, and a rash that often appears on the palms of the hands and soles of the feet. Hepatitis B may cause fatigue, nausea, and joint pain weeks to months after exposure.
Itching and Irritation
Persistent genital itching, especially around the vulva, vaginal opening, or penile shaft, can point to trichomoniasis, herpes (during or before an outbreak), or genital warts. Pubic lice cause intense itching in the groin area, usually starting within a few days to two weeks of contact. The itching tends to be worse at night.
Itching alone is common and has many non-STI causes, from yeast infections to skin irritation. But itching combined with discharge, sores, or pain during sex raises the likelihood of an STI.
When Symptoms Don’t Show Up at All
This is the part that catches most people off guard. The majority of chlamydia infections and nearly half of gonorrhea cases produce no symptoms whatsoever. Herpes can be mild enough that people mistake it for an ingrown hair or razor burn. HPV often causes no symptoms until a routine screening catches abnormal cells years later. Syphilis can hide for decades between stages.
This is why screening matters even when you feel perfectly fine. Current guidelines recommend at least one HIV test for all adults and adolescents ages 13 to 64. Sexually active women under 25 should be screened annually for chlamydia and gonorrhea. Anyone with new or multiple partners, or specific risk factors, benefits from more frequent testing.
How Soon Symptoms Appear
If symptoms do develop, the timeline varies significantly by infection:
- Herpes: 2 to 12 days, average 4 days
- Gonorrhea: usually within 2 to 8 days, sometimes up to 2 weeks
- Chlamydia: 1 to 3 weeks
- Trichomoniasis: 5 to 28 days
- Syphilis: 10 to 90 days, average 21 days
- HIV: flu-like symptoms may appear within 1 to 2 weeks, then silence for months to years
- Hepatitis B: usually around 6 weeks, but up to 6 months
A negative test taken the day after a possible exposure won’t catch most infections. Each STI has a window period before it becomes detectable, which is why testing is often recommended a few weeks after a potential exposure, with follow-up testing for infections like HIV that take longer to show up reliably.