Sexual Health

Cause: Having vaginal, anal, or oral sex with someone who has chlamydia.

Symptoms: abnormal vaginal discharge, burning sensation when peeing, discharge from the penis, pain and swelling in one or both testicles (although this is less common), rectal pain, discharge, and bleeding. Although most people with the infection have no symptoms.

Damage: If a woman does not receive treatment, chlamydia can spread into the uterus or fallopian tubes, causing PID (see PID below). Symptomatic PID occurs in about 10-15% of women who do not receive treatment. Chlamydia can also cause subclinical inflammation of the upper genital tract (“subclinical PID”); both acute and subclinical PID can cause long-term damage to the fallopian tubes, uterus, and surrounding tissues. Chlamydia damage can lead to chronic pelvic pain, tubal factor infertility, and potentially fatal ectopic pregnancy.

Some patients with PID develop perihepatitis, or “Fitz-Hugh-Curtis Syndrome”. This syndrome includes inflammation of the liver capsule and surrounding peritoneum, which can cause right upper quadrant pain.

When pregnant, untreated chlamydia can lead to pre-term delivery, ophthalmia neonatorum (conjunctivitis), and pneumonia in the newborn.

Reactive arthritis can occur in men and women following infection with or without symptoms. This is sometimes part of a triad of symptoms (with urethritis and conjunctivitis) formerly referred to as Reiter’s Syndrome.

Prevalence: Chlamydia is most common among young people. The CDC estimates that there were four million chlamydial infections in 2018. Chlamydia is also the most frequently reported bacterial sexually transmitted infection in the United States. It is difficult to account for many cases of chlamydia. Two-thirds of new chlamydial infections occur among youth aged 15-24 years.3 Estimates show that 1 in 20 sexually active young women aged 14-24 years has chlamydia.

Cause: Having vaginal, anal, or oral sex with someone who has gonorrhea

Symptoms: Gonorrhea often has no symptoms, but some symptoms can include: painful or burning sensation when peeing, increased vaginal discharge, vaginal bleeding between periods, white, yellow, or green discharge from the penis, painful or swollen testicles (although this is less common), rectal discharge, anal itching, soreness, bleeding, and painful bowel movements.

Damage: Untreated gonorrhea can cause serious and permanent health problems.

In women, untreated gonorrhea can cause pelvic inflammatory disease (PID). Some of the complications of PID are formation of scar tissue that blocks fallopian tubes, ectopic pregnancy (pregnancy outside the womb), infertility (not being able to get pregnant), and long-term pelvic/abdominal pain.

In men, gonorrhea can cause a painful condition in the tubes attached to the testicles, which can, in rare cases, lead to infertility.

Rarely, untreated gonorrhea can also spread to your blood or joints. This condition can be life-threatening.

Untreated gonorrhea may also increase your chances of getting or giving HIV.

Prevalence: The CDC estimates that approximately 1.6 million new gonococcal infections occurred in the United States in 2018, and more than half occurred among young people aged 15-24. Gonorrhea is the second most commonly reported bacterial sexually transmitted infection in the United States.

Cause: You can get syphilis by direct contact with a syphilis sore during vaginal, anal, or oral sex.

Symptoms: Primary stages of syphilis include sores that usually occur in, on, or around the penis, vagina, anus, rectum, and lips or in the mouth.

Sores are usually (but not always) firm, round, and painless. Because the sore is painless, you may not notice it. The sore usually lasts 3 to 6 weeks and heals regardless of whether you receive treatment. Secondary, Latent, and Tertiary stages vary in symptoms. See here for more information.

Damage: Syphilis is curable with the right antibiotics from your healthcare provider. However, treatment might not undo any damage the infection can cause.

Prevalence: During 2021, there were 176,713 new cases of syphilis (all stages). Gay, bisexual, and other men who have sex with men (MSM) are experiencing extreme effects of syphilis. However, case rates are increasing among heterosexual men and women in recent years. Congenital syphilis continues to be a concern in the United States. Congenital syphilis occurs when a pregnant person passes syphilis to their baby. Final 2021 data show more than 2,800 cases of congenital syphilis.

Cause: Most people who get HIV get it through anal or vaginal sex or sharing needles, syringes, or other drug injection equipment (for example, cookers).

Symptoms: Most people have flu-like symptoms within 2 to 4 weeks after infection. Symptoms may last for a few days or several weeks. Having these symptoms alone doesn’t mean you have HIV. Other illnesses can cause similar symptoms. Some people have no symptoms at all. The only way to know if you have HIV is to get tested.

Damage: HIV is a viral infection. It targets and gradually weakens the body’s immune system by damaging cells called CD4 T cells. This damage means that, over time, the body becomes less able to fight off other infections.

If the immune system becomes impaired enough, infections that are typically mild can be life-threatening. These are known as opportunistic infections.

When a person contracts HIV, if they do not receive treatment, the infection will typically progress through three stages:

Acute infection: Soon after contracting the virus, the person has a large amount of HIV in their blood, and the risk of the virus transmitting to others is high. Some people may experience flu-like symptoms, but others will have no symptoms.

Chronic infection: Without treatment, this stage can last for a decade or longer. People may not have any symptoms, but the virus can still transmit to other people.

Stage 3 infection (also known as AIDS): At this stage, a person’s immune system is badly damaged, and their CD4 cell count drops below 200 cells per cubic millimeter (cells/mm3) of blood. They will become vulnerable to opportunistic infections, and the risk of viral transmission can be high.

Prevalence: In 2021, 36,136 people received an HIV diagnosis in the United States and dependent areas. The annual number of new diagnoses decreased by 7% from 2017 to 2021.

An estimated 1.2 million people in the United States had HIV at the end of 2021, the most recent year for which this information is available. Of those people, about 87% knew they had HIV.

In 2021, male-to-male sexual contact accounted for 67% (24,107) of all new HIV diagnoses in the United States and dependent areas. In the same year, heterosexual contact accounted for 22% (8,059) of all HIV diagnoses.

Cause: You can get genital herpes by having vaginal, anal, or oral sex with someone who has the infection. You can get herpes if you have contact with:

• A herpes sore

• Saliva from a partner with an oral herpes infection

• Genital fluids from a partner with a genital herpes infection

• Skin in the oral area of a partner with oral herpes

• Skin in the genital area of a partner with genital herpes

• From a sex partner who does not have a visible sore or is unaware of their infection

• If you receive oral sex from a partner with oral herpes

Symptoms: Most people with genital herpes have no symptoms or have very mild symptoms. Mild symptoms may go unnoticed or be mistaken for other skin conditions like a pimple or ingrown hair. Because of this, most people do not know they have a herpes infection.

Herpes sores usually appear as one or more blisters on or around the genitals, rectum, or mouth. This is known as having an “outbreak.” The blisters break and leave painful sores that may take a week or more to heal. Flu-like symptoms (e.g., fever, body aches, or swollen glands) also may occur during the first outbreak.

People who experience an initial outbreak of herpes can have repeated outbreaks, especially if they have HSV-2. However, repeat outbreaks are usually shorter and less severe than the first outbreak. Although genital herpes is a lifelong infection, the number of outbreaks may decrease over time.

Damage: Genital herpes can cause painful genital sores and can be severe in people with suppressed immune systems.

If you touch your sores or fluids from the sores, you may transfer herpes to another body part, like your eyes. Do not touch the sores or fluids to avoid spreading herpes to other parts of your body. If you do touch the sores or fluids, quickly wash your hands thoroughly to help avoid spreading the infection.

Prevalence: Genital herpes is common in the United States. In 2018, CDC estimates show there were 572,000 new genital herpes infections in the United States among people aged 14 to 49.

Cause: You can get HPV by having vaginal, anal, or oral sex with someone who has the virus. It is most commonly spread during vaginal or anal sex. It also spreads through close skin-to-skin touching during sex. A person with HPV can pass the infection to someone even when they have no signs or symptoms.

Symptoms: Some people develop warts from certain low-risk HPV infections, but the other types (including the high-risk types) have no symptoms.

If a high-risk HPV infection lasts for many years and causes cell changes, you may have symptoms. You may also have symptoms if those cell changes develop into cancer. Which symptoms you have depends on which part of the body is affected.

Damage: There are two categories of sexually transmitted HPV. Low-risk HPV can cause warts on or around your genitals, anus, mouth, or throat. High-risk HPV can cause various cancers:

• Cervical cancer

• Anal cancer

• Types of oral and throat cancer

• Vulvar cancer

• Vaginal cancer

• Penile cancer

Most HPV infections go away on their own and don't cause cancer. But sometimes, the infections last longer. When a high-risk HPV infection lasts for many years, it can lead to cell changes. If these changes are not treated, they may get worse over time and become cancer.

Prevalence: HPV is the most common STI. There were about 43 million HPV infections in 2018, many among people in their late teens and early 20s. There are many different types of HPV. Some types can cause health problems, including genital warts and cancers. But there are vaccines that can stop these health problems from happening. HPV is a different virus than HIV and HSV (herpes).

Cause: Sexually active people can get trich by having sex without a condom with a partner who has trich.

In women, the infection is most commonly found in the lower genital tract (vulva, vagina, cervix, or urethra). In men, the infection is most commonly found inside the penis (urethra). During sex, the parasite usually spreads from a penis to a vagina or from a vagina to a penis. It can also spread from a vagina to another vagina.

Symptoms: About 70% of people with the infection do not have any signs or symptoms. When trich does cause symptoms, they can range from mild irritation to severe inflammation. Some people get symptoms within 5 to 28 days after getting the infection. Others do not develop symptoms until much later. Symptoms can come and go.

Men with trich may notice:

• Itching or irritation inside the penis

• Burning after peeing or ejaculating

• Discharge from the penis

Women with trich may notice:

• Itching, burning, redness, or soreness of the genitals

• Discomfort when peeing

• A clear, white, yellowish, or greenish vaginal discharge (i.e., thin discharge or increased volume) with a fishy smell

Having trich can make sex feel unpleasant. Without treatment, the infection can last for months or even years.

Damage: Trich can increase the risk of getting or spreading other sexually transmitted infections. For example, trich can cause genital inflammation, making it easier to get HIV or pass it to a sex partner.

Pregnant people with trich are more likely to have their babies early. Also, their babies are more likely to have a low birth weight (less than 5.5 pounds).

Prevalence: In the United States, CDC estimates that there were more than two million trichomoniasis infections in 2018. However, only about 30% develop any symptoms of trich. Infection is more common in women than in men. Older women are more likely than younger women to have the infection.

Cause: You are more likely to get PID if you:

• Have an STD and do not get treated

• Have more than one sex partner

• Have a sex partner who has sex partners other than you

• Have had PID before

• Are sexually active and are age 25 or younger

• Douche

• Use an intrauterine device (IUD) for birth control. However, the small increased risk is mostly limited to the first three weeks after the IUD is placed inside the uterus by a doctor.

Symptoms: You may not realize you have PID because your symptoms may be mild, or you may not experience any symptoms. However, if you do have symptoms, you may notice:

• Pain in your lower abdomen

• Fever

• An unusual discharge with a bad odor from your vagina

• Pain and/or bleeding when you have sex

• Burning sensation when you urinate

• Bleeding between periods

Damage: If diagnosed and treated early, the complications of PID can be prevented. Some of the complications of PID are:

• Formation of scar tissue both outside and inside the fallopian tubes that can lead to tubal blockage

• Ectopic pregnancy (pregnancy outside the womb)

• Infertility (inability to get pregnant)

• Long-term pelvic/abdominal pain

Prevalence: PID is a frequent and important infection that occurs among women of reproductive age. Based on data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 cycle, the estimated prevalence of self-reported lifetime PID was 4.4% in sexually experienced women of reproductive age (18–44 years).

This equates to an estimated 2.5 million women in the United States with a reported lifetime history of PID diagnosis. The prevalence was highest in women at increased risk, such as those with previous sexually transmitted infections (STIs).