The Most Common Sexually Transmitted Diseases

A sexually transmitted disease (STD) is any disease that is spread primarily by sexual contact. One person passes the infection to another during oral, vaginal, or anal sex.

STDs are some of the most difficult diseases to catch. You have to be up close and personal to spread them. So why are STDs so common? The answer may be that people don't know how to recognize, treat, and prevent them. Or when they do, they often don't do so effectively.

This article explores some of the most common sexually transmitted diseases in the U.S. It also discusses their causes and symptoms.

Most Common Sexually Transmitted Diseases

Verywell / Brianna Gilmartin

Not all diseases that affect the sex organs are considered STDs. In fact, some are not related to sex at all. Others aren't transmitted during sex, but occur as a result of it. For example, urinary tract infections (UTIs) can occur when the tissues in your urinary tract are irritated by sex. Irritated tissues are more likely to become infected.

Here are some common STDs and diseases associated with sex, along with their symptoms.


Chlamydia is the most common curable bacterial STD. It infects the cervix, which is the opening to the uterus or womb. It can also infect the urethra in a penis.

Its most frequent symptoms are pain during sex and discharge from the penis or vagina.

The reason chlamydia is one of the most common STDs is that most people who get chlamydia don't have symptoms for weeks, months, or even years. In other words, they're asymptomatic.

The Centers for Disease Control and Prevention (CDC) recommends that you be screened for sexually transmitted infections if you are under 25 years old and sexually active. They also recommend screening if you have any of these risk factors:

  • you have a new sex partner
  • you have a sex partner with an STI
  • you have more than one sex partner
  • you have a sex partner who is having sex with other people

The disease can do a lot of damage to your body in the long run. It can cause infertility by blocking the reproductive tract in men and women. Latex condoms can prevent the spread of this disease.


Gonorrhea, otherwise known as "the clap," is another common bacterial STD. It often infects the same organs as chlamydia and has similar long-term effects.

If you have gonorrhea, it may burn when you urinate. The disease can also cause white, yellow, or green discharge from the penis. It's important to know that many people with gonorrhea don't have symptoms.


The Centers for Disease Control and Prevention (CDC) estimates that there are more than 120 cases of gonorrhea for every 100,000 people in the United States. That number has been growing for several years.

Be aware, too, that gonorrhea can also infect your throat if you get it by having oral sex.

Gonorrhea does not always go away when it's treated by antibiotics. There is a growing problem of antibiotic-resistant gonorrhea.


This photo contains content that some people may find graphic or disturbing.

primary syphilis

DermNet / CC BY-NC-ND

Syphilis is a common STD with a long history. It's caused by the bacterium Treponema pallidum and can lead to serious health problems if left untreated.

Syphilis is transmitted by when you come into direct contact with syphilis sores. They are usually found on the outside or inside of sex organs. They can also appear on your mouth or rectum. That means it can be transmitted by oral, vaginal, or anal sex. In fact, some scientists think that oral sex is responsible for the rise of syphilis in men who have sex with men.


Syphilis sores can appear on areas not covered by a condom. Condoms lower your risk of getting syphilis, but they don't eliminate it.

At first, syphilis sores (chancres) are small and painless. They may heal by themselves, but that doesn't mean the disease is gone. It's just become harder to spot and treat.

Mycoplasma Genitalium or MG

Mycoplasma genitalium (MG) is starting to emerge as a major cause of infections in the cervix. MG also causes inflammation of the urethra in the penis. MG can cause the same kinds of symptoms as gonorrhea and chlamydia. In 2007, a well-known study of U.S. teens found that MG infected more people than gonorrhea.

Why did it take so long to recognize MG's importance? Because most cases don't cause symptoms. It was hard to identify until new technology became available. There is still no diagnostic test for MG cleared by the Food and Drug Administration (FDA) for use in the United States.


More research on MG is needed. Current research has found a link between MG and serious long-term health problems such as infertility from pelvic inflammatory disease.


Trichomoniasis is the most common curable STD. It affects more women than men. This infection can seem like a yeast infection or bacterial vaginosis since the symptoms are similar. Symptoms include:

Men with trichomoniasis don't usually have symptoms. If you have been diagnosed with the disease, make sure your partner gets treated. Even if trichomoniasis does not seem to be affecting your partner much, they can still give it back to you, no matter what their sex.

Human Papilloma Virus (HPV)

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genital warts

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Human papillomavirus (HPV) may be the most common STD. Studies from before the HPV vaccine was available showed that around three-quarters of sexually active people had HPV at some point. One quarter of women were infected at any given time.

HPV is sometimes called "the cervical cancer virus," but only a few types of HPV are linked to cancer. These types are linked to more than just cervical cancer (including penile and anal cancer). Other types cause genital warts, other warts, or no symptoms at all.

There is no cure for HPV, but its symptoms can be treated. Infections can sometimes resolve on their own. It is recommended that 11- to 12-year-olds get the HPV vaccine to protect them from the most common strains of the virus.


The CDC also recommends the HPV vaccine for adults age 26 and under if they were not vaccinated earlier.


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genital herpes

DermNet / CC BY-NC-ND

Herpes (HSV) is an STD caused by a virus. It comes in two forms: HSV1 and HSV2. HSV1 is often associated with cold sores, and HSV2 is often associated with genital sores. However, it is possible to pass herpes from the mouth to the genitals and vice versa.

Herpes cannot be cured. But its symptoms can be treated with antiviral drugs. You can pass the virus to someone else even if you do not have any sores or other symptoms.

Using a condom lowers the risk of spreading herpes. You can still get herpes even if you use a condom, though.


Herpes can be spread by having sex, but it can also be passed through skin-to-skin contact.


Human immunodeficiency virus (HIV) is the virus that can cause AIDS. It can only be spread by an exchange of bodily fluids. HIV can be spread through:

  • Semen
  • Vaginal fluids
  • Breast milk
  • Blood

HIV cannot be passed by casual contact.

Today, most people with HIV are treated with a combination of drugs known as highly active anti-retroviral therapy (HAART), or combined anti-retroviral therapy (cART). These therapies cannot cure the disease, but they can reduce the chances of HIV leading to AIDS.


HIV is no longer a death sentence. Many people with the virus are living long and healthy lives.


There are several types of hepatitis. Different viruses are spread through various routes, but they all damage the liver. The type of hepatitis most often spread by sexual contact is hepatitis B (HBV). However, in rare cases, it's also possible to get hepatitis C by having sex with an infected person.

Over time, hepatitis B can lead to scarring of the liver, cirrhosis, and liver cancer. Fortunately, there is a vaccine that can protect you.


Approximately 1.25 million people in the United States have a chronic HBV infection.

Bacterial Vaginosis

Bacterial vaginosis (BV) is a condition where the healthy bacteria in the vagina disappear and are replaced by different organisms. Symptoms include burning and itching around the vagina, white or gray discharge, and a strong fishy odor that is more noticeable after sex.

Some people question whether or not BV is an STD, but there is a link between BV and having a new sex partner or multiple sex partners. You can take antibiotics to get rid of BV, but it can show up again.


Bacterial vaginosis can increase the risk of HIV, pelvic inflammatory disease, and pre-term birth (babies born too early).


This photo contains content that some people may find graphic or disturbing.


DermNet / CC BY-NC-ND

Chancroid is a disease caused by the bacterium Haemophilus ducreyi. Chancroid infections raise the risk of getting HIV. This STD isn't as common in the United States as it is in other parts of the world.

The ulcers caused by chancroid are often larger than those caused by syphilis. They can be more painful, too. Early on, it can be hard to tell these two infections apart.

Lymphogranuloma Venereum

Lymphogranuloma venereum (LGV) is an STD caused by bacteria. At one time, LGV mostly affected people in developing countries. However, it is now on the rise worldwide.

In 2003, an LGV outbreak happened among men who have sex with men (MSM) in the Netherlands. Since then, it has been found in some groups of MSM across western Europe, North America, and Australia.

LGV is caused by a type of Chlamydia trachomatis. It can raise the risk of getting or spreading HIV.

Molluscum Contagiosum

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molluscum contagiosum

DermNet / CC BY-NC-ND

Molluscum contagiosum is a skin disease that most often affects young children and adults with weaker immune systems. It is usually spread by direct skin contact. It can also be spread by sharing towels and linens.

Molluscum contagiosum causes small pink, white, or skin-colored bumps to show up almost anywhere on the body. The bumps often have a pit in the center. Usually, they go away on their own within weeks or months.

Methicillin-Resistant Staphylococcus Aureus

Methicillin-resistant Staphylococcus aureus (MRSA) may not be thought of as an STD, but new research shows that it probably can be spread sexually. MRSA is a bacterial infection that has become resistant to many common antibiotics.

Most people who get MRSA are in ​the hospital or other medical settings, but it can also be passed by direct skin-to-skin contact.

Nongonoccocal Urethritis

Nongonoccocal urethritis (NGU) causes urethritis. Urethritis is an inflammation of the tubes that carry urine from your bladder to the outside of your body. NGU is inflammation caused by something other than gonorrhea.

The two most common causes of NGU are chlamydia and MG. Symptoms of NGU include burning when you urinate and discharge from the head of the penis. However, it is important to know that most people with NGU have no symptoms at all.

Pubic Lice

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pubic lice

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Pubic lice are often called "crabs." They are a form of lice that live on the hair in the genital area. They can sometimes live on other parts of the body covered with thick or coarse hair. Pubic lice sometimes live in the armpits and eyebrows, for example.

They are usually spread by sexual contact, but it's possible to get them from infested linens and clothing.

Symptoms include itching in the genital area and lice or eggs you can see. Pubic lice are not the same as head lice. They almost never infest the hair on the head.

It isn't true that you have to shave off all your pubic hair if you get infected with pubic lice.


This photo contains content that some people may find graphic or disturbing.

scabies on buttocks

DermNet / CC BY-NC-ND

Scabies is a contagious skin disease. It is not always sexually transmitted.

Scabies is caused by the parasite Sarcoptes scabei. It causes a very itchy rash that gets worse at night. The rash is most often found in folds of skin, such as between the fingers, on the wrists and ankles, and in the genitals.

Scabies is highly contagious. The mites can live for days off the human body. You can get scabies through:

  • Close personal contact
  • Skin-to-skin contact
  • Shared clothing, towels, or bedding


STDs are diseases spread by oral, vaginal, or anal sex. Some STDs can also be spread by skin-to-skin contact or shared clothing and linens.

Some STDs can be cured and others can't. Some have symptoms you can see or feel, and others have no symptoms at all. For that reason, it's really important to be tested for STDs to protect your health and your partner's.

Frequently Asked Questions

  • What is the most common bacterial STD?

    Chlamydia is the most frequently reported bacterial STD in the United States. The CDC estimates that there were four million cases of chlamydia in 2018. That number may be even higher since most people with chlamydia do not have symptoms. They may not know to get tested.

  • What is the most common viral STD?

    Human papillomavirus (HPV) is the most common viral STD in the United States. In 2018, there were about 43 million HPV infections. Many of those affected are in their late teens and early 20s.

  • How do you know if you have an STD?

    Some STDs cause symptoms. Others may not. It's important to get tested to know for sure whether you have an STD. You can find free and confidential testing near you at the CDC's site GetTested.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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