Medically reviewed on September 30, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Sexually transmitted diseases (STDs) are infections or diseases that spread primarily through sexual intercourse. According to the World Health Organization (WHO), more than one million new infections occur worldwide every day. In all, there are more than 20 different types of STDs, each with a unique list of symptoms and cures.
If you attended a school with a comprehensive sex education program, you’ve likely heard about STDs before. But have you ever wondered what the most common STD is?
In this guide to STDs, we examine which are the most prevalent, what they look like, and how they’re transmitted.
A sexually transmitted disease is any bacteria, virus, or parasite that can pass through oral, vaginal, or anal sex. More rarely, STDs like a genital herpes, hepatitis B, or chlamydial infection can spread through non-sexual, skin-to-skin contact or during childbirth.
Sometimes, healthcare providers use the term ‘sexually transmitted infection’ (STI) to refer to these health conditions. Some prefer the term sexually transmitted infections over diseases, as not every sexually transmitted infection becomes a disease. Additionally, there is less of a stigma associated with the word infection than with the word disease. Either way, these two terms refer to the same general concept: afflictions passed through sexual intercourse.
In people assigned female at birth (AFAB), the most common STD is human papillomavirus (HPV). HPV spreads the same way most STIs do—through unprotected oral, anal, or vaginal sex with an affected individual.
One of the reasons that HPV spreads easily is its lack of visible symptoms. It can stay dormant in the body and not show symptoms for years. Thus, you may be wondering, how long can a STD stay dormant without symptoms? Unfortunately, this is still unknown. Many women will not experience any telltale signs, though genital warts may occur. When HPV is left untreated, it can cause certain types of cancer, including:
Does HPV go away on its own? What happens if it goes untreated? With all of this in mind, there is some good news about HPV. First, 90% of all HPV cases resolve themselves within two years. Second, there is an HPV vaccine, which the Centers for Disease Control and Prevention (CDC) recommends everyone receives at the age of 11 or 12. If you received your routine vaccines in school at that age, you likely have additional protection against HPV. If you were not vaccinated for HPV, consider speaking with your healthcare provider for more information.
Finally, HPV is easy to test for. Using an at-home STD test, you can determine if you’re a carrier of the human papillomavirus.
Believe it or not, in people assigned male at birth (AMAB), the most common sexually transmitted disease is also HPV. However, most men with HPV will never experience symptoms. While HPV can still lead to genital warts or certain types of cancer in men, they’re generally at less risk overall (though they can still spread the infection to their partner or partners).
Considering that there were 43 million HPV infections in 2018, you can understand why it’s the most common STD in the U.S. among people of any gender.
Aside from HPV, there are other common STDs to watch out for. Here are some of the most prevalent in people of any gender, race, or sexual orientation.
After HPV, syphilis is one of the most common STDs. Caused by an overgrowth of the bacteria treponema pallidum, syphilis can be spread during sexual contact, as well as from mother-to-child during pregnancy. Syphilis has three stages: primary, secondary, and tertiary.
In its earliest stages, syphilis often appears as a small, usually painless sore on the genitals, anus, or mouth. Nearby lymph nodes may also swell. If left untreated, syphilis can cause a (non-itchy) skin rash on the hands and feet.
By testing for syphilis often, you can spot it early and treat it with antibiotics.
Another common STI in people of all genders is chlamydia, which is caused by a bacteria known as chlamydia trachomatis. Chlamydia can transfer between partners during sexual intercourse or (in rarer cases) from mother-to-child during childbirth.
Although symptoms are uncommon, people with chlamydia may experience:
Keep in mind that even though you may not see symptoms, chlamydia (like most STIs) can still spread without visible signs. That’s why testing for chlamydia is the best way to prevent spreading it—and if you find out you have the STI, you can typically treat it using antibiotics.
Gonorrhea is another common bacteria-caused STI that can be passed through sexual intercourse or from mother-to-child during childbirth. In men, symptoms may include abnormal discharge from the penis and/or painful urination; and in women, symptoms may include painful urination, bleeding between periods, and/or an increase in vaginal discharge.
As you may notice, the symptoms of gonorrhea are quite like those of chlamydia. If you experience any of these symptoms, the best way to determine the cause is through a general STD test, though you can also take a specific gonorrhea test. And don’t worry if your test comes back positive—your healthcare provider can prescribe antibiotics for treatment.
Sometimes shortened to “trich,” trichomoniasis is a common STI caused by the protozoan parasite trichomonas vaginalis. Despite the name of the parasite, men and women both can catch trich through unprotected sex.
Although roughly 70% of people do not experience symptoms from trichomoniasis, those who do may notice the following signs 5–28 days after infection:
Because symptoms are so rare, the best way to confirm a case of trich is to take a trichomoniasis test. If your test comes back positive, your healthcare provider may prescribe antibiotics as treatment.
STDs may be more common than you think, but that doesn’t mean you should accept that catching one is inevitable. Ultimately, if you’re sexually active, the best way to protect yourself and your sexual partner(s) is through safe sex and regular testing—whether you notice symptoms or not.
With at-home tests from Everlywell, you can be proactive about your sexual health. Choose from various sexual health tests, including tests for trichomoniasis, gonorrhea, HIV, and syphilis. If you want to test for multiple STDs at once, we also offer comprehensive STD tests for men and women.
Plus, we ship all at-home tests in discreet packaging with no visual indicators. This way, you can take your test from the comfort and privacy of your own home. Reach out today to learn more.
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