Sexually transmitted infections (STI) are becoming increasingly more common. In 2018, the CDC reported that combined cases of syphilis, gonorrhea, and chlamydia reached an all-time high in the U.S. These infections are spread from one person to another during vaginal, anal, and/or oral sex. STIs are very common, and many people who contract STIs do not have any symptoms.

Anyone of any age can contract an STI, and there is no shame behind getting tested or being positive for an STI. They are a part of the reality of being sexually active, and it's important to be knowledgeable to protect yourself and your partner(s). This is why it is so important to get tested, as untreated STIs can lead to serious health problems.

The good news is that most common STIs are easy to treat and it can be very easy to get tested. Many people may feel apprehensive about testing, particularly because of the stigma that surrounds the subject of STIs. But having STIs or getting tested for them are nothing to be ashamed about, it's a part of being responsible for your health and caring for your body. If you are sexually active, it's very important to be knowledgeable about STIs and learn how you can protect yourself.

The 6 Most Common STIs and How They Can Impact Your Health

1. Human Papillomavirus (HPV)

HPV is the most common STI in the United States. There are more than 14 million new cases each year in the U.S.

  • Symptoms: Most sexually active people will get HPV at some point in their life. The infection can be spread even if there are no symptoms. In fact, symptoms of HPV do not show up for most people until they develop health issues. HPV infections are usually not harmful and go away on their own within two years. However, some types of HPV can lead to serious health issues if left untreated, which include genital warts and cervical cancer.
  • Treatment: There is no treatment for HPV itself, but there are treatments for the health problems caused by HPV. Genital warts can be treated by healthcare providers or with prescription medication. Cervical pre-cancer and other HPV-related cancers can be treated more easily when diagnosed and treated early, which is why it is so important to get tested. Those with vaginas should also keep up on regular screenings like the pap smear test which can detect cervical abnormalities resulting from an HPV infection. 
  • Prevention: The HPV vaccine is recommended for both sexes at age 11 or 12, but can first be given at 9 years old. The vaccination can be given to anyone through the age of 26 if not previously vaccinated. This is because the effectiveness of the vaccine begins to decline after age 18.
  • Long-Term Impact: HPV will have a low impact if asymptomatic and/or treated early, but may have significant impact if it goes undetected and causes pre-cancerous or cancerous growths. 

2. Chlamydia

Chlamydia is a bacterial infection that has almost three million new cases in the U.S. each year. It is the second most common STI in the United States.

  • Symptoms: Signs of chlamydia include discharge from the penis or vagina and/or burning during urination. However, many people who contract chlamydia experience no symptoms.
  • Treatment: Chlamydia should be treated with antibiotics as soon as possible by your doctor as it can lead to serious health problems if left untreated. Women can develop pelvic inflammatory disease (PID) and men can develop a condition that causes painful inflammation of the tube that carries sperm.
  • Prevention: The best way to avoid getting chlamydia while being sexually active is to use condoms and dental dams. Getting tested regularly is an important part of sexual health, and it can prevent others from unknowingly spreading the infection to others. Many chlamydia tests can be as simple as urinating into a cup, while others involve rubbing the genitals with a cotton swab. The cell samples collected are tested for chlamydia bacteria.
  • Long-Term Impact: Low if caught and treated early; more significant if untreated.

3. Trichomoniasis

Also known as “Trich”; one of the most common STIs. Millions of people get this STI every year. This STI is caused by a tiny parasite called trichomona, which spreads during unprotected sexual contact through the exchange of sexual fluids. It can spread from vulva-to-vulva contact, sharing sex toys, or even touching your own genitals after your partner's. This STI easily infects the genitals, but does not affect other areas of the body like the mouth or anus. Luckily, it is easily curable when treated.

  • Symptoms: Most people with trichomoniasis do not experience symptoms, so they often do not know they have it until getting tested. Vaginitis is the most common symptom, which is when the vulva or vagina is irritated. Trich can also cause painful or frequent urination, discharge, odor, and genital irritation/itching.
  • Treatment: In most cases, trichomoniasis is very easy to treat. The process for testing for trichomoniasis is usually done by your doctor taking cell samples from the genitals with a cotton swab. The test can also be done by urinating into a cup. If you are tested positive for trich, your doctor will prescribe antibiotics (metronidazole or tinidazole) to treat the infection. The antibiotics usually work in one dosage. It's also important to abstain from sexual contact for about a week after receiving treatment to reduce the risk of spreading the infection. You can get trichomoniasis more than once if exposed again, so be sure to use condoms and get tested regularly. Untreated trichomoniasis also increases your chances of getting and/or spreading other STIs such as HIV.
  • Prevention: Since this STI is spread through genital contact with sexual fluids, the best way to prevent trich is to use condoms during vaginal or anal sex. It’s also important to be conscious of other sexual acts that involve spreading sexual fluids such as sharing sex toys or intimate touching.
  • Long-Term Impact: Low to moderate; easily treated.

4. Gonorrhea

Also known as “the clap”. There are more than 800,000 new cases in the United States each year. This STI occurs when there is a bacteria infecting the lining of the reproductive tract. Gonorrhea can also infect the urethra, throat, mouth, eyes, and anus of both men and women. It is spread through sexual contact of the penis, vagina, mouth, or anus of someone who is infected. If pregnant and infected with gonorrhea, one can pass the infection to the baby during childbirth. Not to worry, this STI is treatable.

  • Symptoms: Many people may not realize that they have gonorrhea because there can be little to no symptoms. If symptoms do show up within a week of infection, they include pain or burning during urination, bloody or yellowish abnormal discharge from the vagina, and bleeding between periods. For those with penises, symptoms include yellow, white, or green discharge from penis, pain or burning during urination, and pain or swelling in the testicles. Gonorrhea can also infect the anus, and symptoms can include itching, discharge, and pain when voiding the bowels. This infection can also show up in the throat, which (when symptoms are present) manifests usually as a sore throat.
  • Treatment: Luckily, gonorrhea is usually easy to get rid of when treated. If tested positive, your doctor will prescribe antibiotics. Gonorrhea can resist antibiotics, so your doctor may prescribe two different ones, in the form of a shot and a pill.
  • Prevention: Since gonorrhea is spread through sexual fluids like semen and vaginal fluids, the best method of prevention aside from abstinence is condoms.
  • Long-Term Impact: Can be significant if left untreated.

5. Genital Herpes

Herpes is a common viral infection that causes sores on the genitals and/or mouth. More than half of Americans have oral herpes and about 1 out of 6 have genital herpes. This STI is caused by two different but similar viral infections: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). HSV-1 typically affects the mouth and HSV-2 typically affects the genitals. However, both kinds can cause sores to manifest around the genitals, anus, inner thighs, mouth, throat, and in rare cases the eyes. Herpes is spread from skin-to-skin contact with infected areas, usually during vaginal, oral, and anal sex. It can also be spread through kissing.

  • Symptoms: Herpes causes outbreaks of itchy and painful sores that come and go. Many people do not recognize these sores as herpes and may not know they are infected. It is also possible to have herpes and not have any symptoms.
  • Treatment: Unfortunately, there is no cure for herpes. However, your doctor can prescribe medication that can ease symptoms and lower the chance of spreading the virus. Although herpes can be very uncomfortable, it is not dangerous to your health.
  • Prevention: The best method of prevention from herpes is to abstain from contact with another person's mouth or genitals. Although this is not necessarily realistic, as we all tend to have intimate contact with others. Using protection such as condoms and dental dams can lower your chance of getting herpes. It’s important to note that these methods can lower your chances of getting herpes, but there is no guarantee of protection as herpes can live on many areas of the body.
  • Long-Term Impact: Moderate to significant; requires managing symptoms in an ongoing way.

6. Syphilis

Syphilis has many other alternate names such as “lues”, “syph”, and “the Pox.” It is a bacterial infection that is spread through vaginal, oral, and anal sex. It is easily cured if detected and treated early.

  • Symptoms: Many people who have syphilis do not have any symptoms, which is one of the reasons why it is so common. This is also why it is so important to get tested, as many STIs do not have obvious symptoms. There are three stages of the syphilis infection. The primary stage occurs when a syphilis sore, called a chancre, shows up on the body. These sores are usually firm and painless, but can also be open and wet. This sore can manifest on the genitals or anus and in rare cases, on the mouth. These are very contagious and can easily pass the infection to others during sex. These sores usually last for about three to six weeks and show up between three weeks to three months after infection. The secondary stage of infection includes rashes on the palms, the soles of the feet, or other parts of the body. This rash usually doesn’t itch, but can show up with flu-like symptoms. This stage can last for two to six weeks and may come and go for up to two years. The late stage of syphilis can lead to tumors, blindness, paralysis, and damage to the brain and nervous system. This is why it is so important to get tested often, as syphilis is fairly easy to treat in the early stages, but can turn very serious in the late stages. The late stage of syphilis can manifest 10 to 20 years after initial infection.
  • Treatment: Syphilis is easy to get rid of if you catch it in the early stages. Syphilis testing usually involves a quick blood sample, or a sample of the fluid from an open sore if present. If tested positive, your doctor will prescribe an antibiotic (penicillin).
  • Prevention: The best way to prevent syphilis besides abstinence is to use condoms and/or dental dams during sex. Since the STI is easy to treat in the beginning stages, getting tested regularly is best to avoid the negative effects of long term infection.
  • Long-Term Impact: Can be significant if left untreated.

Although these are the six most common STIs, there are many others. Planned Parenthood has a comprehensive breakdown of all the most common STIs.

What Should I Do If I Test Positive?

There’s no shame in testing positive for an STI. Being at risk for sexually transmitted infections is a part of being sexually active, and there is nothing shameful or wrong about contracting a STI. The most important thing is to make sure you and your partner(s) are safe and healthy. So it is very important that you communicate to past or current partners of your status, so that they can become aware that they may need to be tested and treated (if possible).

Read our article I Tested Positive for an STI. Now What? for more on this topic.

How Can I Reduce STI Transmission?

Sexual abstinence is the best method of prevention against STIs, although it is the least realistic. Most of us will engage within sexual activity in our lives.

Although not 100% effective, the best way to reduce STI transmission during sexual activity is by using condoms and/or dental dams. Condoms are used to prevent the spread of STIs and pregnancy during penetrative sex or oral, while dental dams are used primarily for prevention in oral sex.

It is important to note that other forms of birth control such as the pill or UTI’s do not protect against the spread of STIs. Getting tested frequently, especially if you are engaging in unprotected sex with different partners, is one of the best ways to ensure you do not spread the STI to others.

Getting tested frequently is also beneficial as it can help you catch an STI in the early stages, as it is best to treat curable STIs as soon as possible. It is recommended to get an STI test between each monogamous relationship and at least once a year as a part of your annual check up.

What If I Have an STI Symptom?

If you suspect that you have an STI, the next step is to get tested. You can get tested for STIs at your primary care doctors office, the health department, your local community health clinic, or your local Planned Parenthood health center.

The cost of STI testing varies on where you get tested, your income, what tests you need, and whether or not you have health insurance. Most insurance plans do cover STI testing, so you may be able to get reduced prices for STI testing if you do have health insurance. Many clinics, such as Planned Parenthood centers, give free or low-cost STI tests depending on your income.