What's the Most Common STD in the US? Top 5 Infections to Watch For

HPV is the most common STD in the United States — so common that the CDC estimates nearly every sexually active person will contract it at some point. Chlamydia is the most commonly reported bacterial STD, with over 1.6 million cases recorded annually. Gonorrhea, syphilis, and herpes round out the top five, and all five are rising. Here is what you need to know about each one.

• HPV affects an estimated 80 million Americans — most never know they have it

• Chlamydia is the most reported STD in the US with 1.6 million+ cases per year, the majority asymptomatic

• Syphilis cases more than doubled between 2018 and 2023, including a sharp rise in congenital syphilis

• Antibiotic-resistant gonorrhea is now a significant public health concern

• 1 in 6 Americans aged 14–49 has genital herpes — most are unaware

1. HPV — The Most Common STD in the US

Human papillomavirus is so prevalent that the CDC considers it nearly universal among sexually active adults who are not vaccinated. There are more than 100 strains of HPV; around 40 affect the genital area. Most infections clear on their own within two years without causing any symptoms or health problems. The infections that do not clear are the concern.

High-risk HPV strains — particularly types 16 and 18 — are responsible for the majority of cervical cancers, as well as cancers of the throat, anus, penis, vagina, and vulva. Low-risk strains cause genital warts. HPV does not show up on standard STI panels; it is detected through Pap smears and HPV-specific cervical screening in women, and through clinical examination of visible warts. There is no treatment for the virus itself, only for the conditions it causes. The HPV vaccine (Gardasil 9) prevents infection with the highest-risk strains and is recommended for all adolescents and adults up to age 45 who have not already been vaccinated.

2. Chlamydia — The Most Reported STD

Chlamydia has been the most commonly reported STD in the US for decades. The CDC recorded over 1.6 million cases in 2022, but the true number is estimated to be significantly higher because up to 70–75% of infections in women and a significant proportion in men produce no symptoms at all. Many cases are simply never tested for.

When symptoms do occur, they include unusual discharge, burning during urination, and pelvic pain in women. Without treatment, chlamydia can progress to Pelvic Inflammatory Disease (PID), causing fallopian tube scarring, chronic pelvic pain, and infertility. It can also increase susceptibility to HIV. The good news: chlamydia is easily cured with a single course of antibiotics — azithromycin or doxycycline — when caught early. The CDC recommends annual screening for all sexually active women under 25 and for older women with new or multiple partners.

3. Gonorrhea — The Antibiotic-Resistance Problem

Gonorrhea was the second most commonly reported STD in 2022, with over 600,000 cases. Like chlamydia, it frequently causes no symptoms — especially in women — and when symptoms do appear, they are often mild enough to be dismissed. Untreated gonorrhea can cause PID, infertility, and increased HIV susceptibility in women, and epididymitis and infertility in men.

What makes gonorrhea particularly concerning today is antibiotic resistance. The bacterium (Neisseria gonorrhoeae) has developed resistance to every first-line antibiotic previously used to treat it. Current treatment relies on a single injectable dose of ceftriaxone. The CDC and WHO are monitoring emerging resistance to ceftriaxone closely, and some treatment failures have already been reported. This makes regular testing and prompt treatment more important than ever, before resistant strains have a chance to establish.

4. Syphilis — The Comeback STD

Syphilis was nearly eliminated in the US in the late 1990s. Since then, rates have risen steadily, more than doubling between 2018 and 2023. The 2022 CDC surveillance report recorded over 200,000 cases of all stages. Particularly alarming is the rise of congenital syphilis — infection passed from mother to baby during pregnancy — which increased by over 750% between 2012 and 2022 and can cause stillbirth, premature birth, and severe infant disability.

Syphilis progresses through four stages. Primary syphilis produces a painless sore (chancre) at the site of infection, often unnoticed. Secondary syphilis causes a characteristic rash on the palms and soles, flu-like symptoms, and sores in the mouth or genitals. Latent syphilis has no symptoms but the bacteria remain active. Tertiary syphilis can damage the heart, brain, eyes, and nervous system — including causing dementia-like symptoms sometimes misdiagnosed as Alzheimer’s disease. Syphilis is curable with penicillin at all stages, but damage caused by late-stage disease may be irreversible. A simple blood test detects it.

5. Herpes (HSV-1 and HSV-2) — The Underestimated Majority

The CDC estimates that approximately 1 in 6 Americans aged 14–49 has genital herpes (HSV-2), and that a much larger proportion carries oral herpes (HSV-1), which can also be transmitted to the genitals. The majority of people with herpes do not know they have it — either because they have never had a recognisable outbreak, or because they attributed mild symptoms to something else.

Herpes is a lifelong infection. The virus lies dormant in nerve cells and can reactivate periodically, causing outbreaks of blisters or sores. Importantly, herpes can be transmitted even when no symptoms are present — through asymptomatic viral shedding. There is no cure, but antiviral medications (aciclovir, valaciclovir, famciclovir) significantly reduce the frequency and severity of outbreaks and lower — though do not eliminate — transmission risk. Herpes is not included in standard STI panels and requires a specific blood test or swab of an active sore. Ask for it by name if you want to be tested.

Trends to Watch: What the Numbers Show

All five infections saw significant case increases in the years leading up to and following the COVID-19 pandemic, which disrupted STI testing and treatment services. Syphilis is experiencing the most dramatic resurgence. Gonorrhea resistance is the most urgent treatment challenge. Chlamydia remains the largest volume problem in terms of reported cases. And HPV, while preventable through vaccination, continues to circulate widely in unvaccinated populations, with vaccination rates still well below public health targets.

How Often Should You Get Tested?

Testing frequency depends on your individual risk profile. Annual testing for chlamydia and gonorrhea is recommended for all sexually active women under 25 and for anyone with new or multiple partners. HIV testing at least once in a lifetime is recommended for all adults aged 15–65, and more frequently for those at higher risk. Syphilis testing is recommended for anyone with new or multiple partners and for all pregnant women. HPV testing is incorporated into routine cervical screening. Herpes testing is not routinely recommended unless you have symptoms or a partner with known herpes.

Tips for Protecting Yourself

• Get vaccinated against HPV — the vaccine is effective at any age up to 45 and is the only way to prevent the most dangerous strains.

• Use condoms consistently — they reduce transmission risk for chlamydia, gonorrhea, syphilis, and HIV significantly, though less effectively for herpes and HPV (which spread through skin contact).

• Get tested before new sexual relationships — knowing your status and your partner’s is the most reliable foundation for safer sex.

• Do not rely on symptoms — the majority of the most common STDs produce no symptoms in the early stages. Testing is the only way to know.

• Complete treatment and follow up — a test of cure is important for gonorrhea given resistance concerns. Ensure partners are also treated to prevent reinfection.

Frequently Asked Questions

Which STD is most commonly missed because it has no symptoms?

Chlamydia. Up to 75% of women and a significant proportion of men with chlamydia experience no symptoms. HPV also produces no symptoms in most cases. Both are detected only through targeted testing.

Can you have more than one STD at the same time?

Yes, co-infections are common. Having one STD generally increases susceptibility to others by causing genital inflammation that disrupts normal protective barriers. Testing for multiple infections simultaneously is routine practice at sexual health clinics.

Is gonorrhea still curable?

Currently yes, with injectable ceftriaxone. However, resistance is emerging and the treatment landscape is narrowing. This is why prompt treatment and test of cure are increasingly important, and why gonorrhea is classified as an urgent public health threat by the CDC and WHO.

Do condoms protect against herpes and HPV?

Partially. Condoms reduce transmission risk by covering the areas most likely to shed virus, but herpes and HPV can be present on skin not covered by a condom. They provide meaningful but not complete protection. Vaccination (for HPV) and antiviral therapy (for herpes) provide additional layers of protection.

Should I ask for a herpes test if I have never had symptoms?

The CDC does not recommend routine herpes blood testing for people without symptoms, because the test can produce false positives and a positive result without symptoms can cause significant distress without clear management implications. However, if you have had a new partner, unprotected sex, or want peace of mind, discuss the pros and cons with a sexual health clinician.

Get Tested Today

Knowing the most common STDs in the US is useful, but knowing your own status is what actually protects your health and your partners. Fast, confidential testing for all five infections described above is available at sexual health clinics and through online services, with most results available within 1–3 days.

Related reading: Can You Have an STD With No Symptoms? · The Rise of Antibiotic-Resistant STDs · STD Symptoms in Women · How Often Should You Get Tested?