The Most Common Sexually Transmitted Diseases

A sexually transmitted disease (STD) is any disease that is spread primarily by sexual contact. One partner transmits the disease-causing organism to the other during sex (oral, vaginal, or anal).

STDs are some of the most difficult diseases in the world to catch since you have to be up close and personal to spread them. So why are STDs so common? The answer is likely because people don't know how to recognize, treat, prevent, and avoid them. Or when they do, they often don't do so effectively.

Most Common Sexually Transmitted Diseases

Brianna Gilmartin / Verywell

Note, however, that not all diseases that affect the sex organs are considered STDs, and some are not related to sex at all. Some are sexually-associated, meaning that they aren't transmitted during sex, but occur as a result of it. For example, urinary tract infections (UTIs) can occur because of tissue irritation and susceptibility to infection that occurs due to intercourse.

Here are some common STDs and sexually-associated diseases and their symptoms that you should be knowledgeable about.


Chlamydia is the most common curable STD. It infects the cervix in women and the penile urethra in men. 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.

Despite the lack of symptoms, it's important to get screened and treated if you think you might have been exposed to chlamydia. If you don't, it can do a lot of damage to your body in the long run, including causing infertility due to blockage of the reproductive tract in men and women. Latex condoms are effective in helping to prevent the disease.


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

Symptoms of gonorrhea include burning when urinating and, in men, white, yellow, or green discharge from the penis. Just as with chlamydia, 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 alone, and that number has been growing for several years.

Be aware, too, that gonorrhea can also infect the throat and be passed via oral sex. Currently, one of the biggest concerns about gonorrhea is treating it, as there is a growing problem of antibiotic-resistant gonorrhea.


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primary syphilis

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Syphilis is a common STD with a notorious history. Caused by the bacterium Treponema pallidum, it can lead to serious complications if left untreated.

Syphilis is transmitted by direct contact with syphilis sores, which can appear on the external genitals and the mouth, as well as in the vagina or rectum. That means it can be transmitted by oral sex, as well as vaginal or anal intercourse. In fact, some scientists think that oral sex is responsible for the rise of syphilis in men who have sex with men.

Because syphilis sores can appear on areas not covered by a condom, condoms only reduce the likelihood of transmission but don't eliminate it entirely.

The small painless sores (chancres) of early syphilis may heal by themselves, but that doesn't mean the disease is gone. It's just become more difficult to detect and treat.

Mycoplasma Genitalium

Mycoplasma genitalium (MG) is starting to emerge as a major cause of cervicitis in women and nongonococcal urethritis in men, conditions also caused by gonorrhea and chlamydia. In 2007, a prominent study of U.S. adolescents found that this previously little-known STD had surpassed gonorrhea in prevalence.

Why did it take so long to recognize the importance of this now common STD? Because most cases of MG don't cause symptoms and it was difficult to identify until the new technology became available. There is still no diagnostic test of MG that is cleared by the FDA for use in the United States.

While the emerging research is still unclear, it is thought that MG is associated with serious long-term consequences, including infertility from pelvic inflammatory disease.


Trichomoniasis is the most common curable STD, with infection more common in women than in men. Some women may mistake this infection for a yeast infection or bacterial vaginosis since the symptoms are similar: frothy discharge, strong vaginal odor, pain during intercourse, irritation, and itching.

Men can get trichomoniasis, but they don't tend to have symptoms. If you are a woman who has been diagnosed with the disease, make sure your partner gets treated.

If your partner is a man, trich may not be affecting him much, but you don't want him giving it back to you. If your partner is a woman, you could also be passing the disease to each other.

Human Papilloma Virus (HPV)

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genital warts

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Human papillomavirus (HPV) is quite possibly the most common STD. Older studies from before the HPV vaccine was available estimated that three-quarters of the sexually active population had HPV at some point during their lives, and one-quarter of women were infected at any given time.

HPV may be known as "the cervical cancer virus," but only a few types of HPV are linked to cancer, and they're linked to more than just cervical cancer (including penile and anal cancer). Others cause genital warts, other warts, or no symptoms at all.

Although HPV is considered incurable, its symptoms can be treated, and infections can sometimes resolveon their own. It is recommended that 11- to 12-year-olds get the HPV vaccine to protect young men and women from the four most common strains of the virus.


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genital herpes

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Herpes (HSV) is another viral STD and it comes in two forms, HSV1 and HSV2. HSV1 is most often associated with cold sores, and HSV2 is most often associated with genital sores. However, it is possible to transmit herpes from the mouth to the genitals and vice versa.

Herpes symptoms can be treated with antiviral drugs, but the virus cannot be cured. People with the herpes virus need to know that they can transmit the virus even when they do not have any sores or other symptoms.

Although using a condom can reduce the risk of herpes transmission, condoms are not 100 percent effective since herpes is spread via skin-to-skin contact.


Human immunodeficiency virus (HIV) is the virus associated with AIDS. It can only be transmitted by an exchange of bodily fluids, including semen, vaginal secretions, ​breast milk, and blood. It cannot be transmitted by casual contact.

Currently, 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). Although these therapies cannot cure the disease, they can reduce the likelihood that infection will progress to AIDS.

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


There are several types of hepatitis. Although the different viruses are transmitted through various routes, they all cause damage to the liver. The type of hepatitis most often associated with sexual transmission is hepatitis B (HBV). However, hepatitis C can also be sexually transmitted.

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

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 a woman's 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 particularly noticeable after intercourse.

Some people question whether or not BV is an STD, but it is associated with having a new sex partner or multiple sex partners. You can take antibiotics to get rid of BV, but it frequently shows up again even after successful treatment.

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


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Chancroid is a genital ulcer disease caused by the bacterium Haemophilus ducreyi. Although not commonly seen in the United States, in other parts of the world chancroid infections are a major risk factor for HIV.

The ulcers caused by chancroid are generally larger and more painful than those associated with syphilis, although the early signs may be mistaken for those of a syphilis infection.

Lymphogranuloma Venereum

Lymphogranuloma venereum (LGV) is an STD that used to be primarily thought of as affecting individuals in developing worlds. However, it is now on the rise worldwide.

After an initial outbreak in men who have sex with men (MSM) in the Netherlands in 2003, LGV has been found in isolated groups of MSM across western Europe, North America, and Australia.

Caused by a type of Chlamydia trachomatis, LGV is closely associated with HIV infection and, as with many other STDs, can actually increase the risk of HIV transmission and acquisition.

Molluscum Contagiosum

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molluscum contagiosum

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Molluscum contagiosum is a skin disease that most often affects young children and adults who have weakened immune systems. It is transmitted by direct skin contact, so it also can be transmitted during sexual contact among adults.

Methicillin-Resistant Staphylococcus Aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is not primarily thought of as an STD, although new research suggests that it probably can be transmitted sexually. Most cases of MRSA are acquired in ​the hospital or other medical settings, though it can also be transmitted by direct skin-to-skin contact.

Nongonoccocal Urethritis

Unlike most of the STDs mentioned in this overview, nongonoccocal urethritis (NGU) is not caused by a specific bacterium or virus. Instead, it is defined as any type of urethritis that is not caused by gonorrhea.

The two most common causes of NGU are chlamydia and Mycoplasma genitalium. Symptoms of NGU include burning when urinating and discharge from the head of the penis. However, as with many STDs, most cases of NGU are asymptomatic.

Pubic Lice

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pubic lice

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Pubic lice (commonly called "crabs") are a form of lice that live on the hair in the genital area and occasionally on other coarse-haired areas of the body, such as the armpits or the eyebrows. They are usually spread by sexual contact, although they also can occasionally be transmitted by infested linens and clothing.

Symptoms include itching in the genital area and visible lice or eggs. You should know that crab lice are not the same as head lice and that they almost never infest the hair on the head.

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


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scabies on buttocks

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Scabies is a contagious skin disease that is not always sexually transmitted. Caused by the parasite Sarcoptes scabei, scabies causes an extremely 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 genital area.

Scabies is incredibly contagious, and the mite can live for days off the human body. It is not only spread by close personal contact, but by skin-to-skin contact in general, shared clothing, towels, and bedding.

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