Sexually transmitted diseases or infections (STDs or STIs) affect tens of millions of people in the United States, according to the Centers for Disease Control and Prevention (CDC).

Men, and others with penises, such as pre-op transgender women, may not realize they’ve acquired an STD, because many have no symptoms. However, that doesn’t mean that STDs aren’t affecting their health.

Not all STDs have symptoms, but when they occur in people with a penis, they can include:

  • pain or burning during urination
  • a need to urinate more frequently
  • pain during ejaculation
  • abnormal discharge from the penis, particularly colored or foul-smelling discharge
  • bumps, blisters, or sores on the penis or genitals

The most common STDs affecting people with a penis include:

Chlamydia

  • Symptoms. Symptoms include pain when urinating, pain in the lower abdomen, and penile discharge.
  • Prevalence. In 2018, there were 610,447 reported cases in men in the United States.
  • Keep in mind. Most people with chlamydia don’t experience symptoms. Because of this, experts believe that many cases go unreported.
  • Treatment. Chlamydia is treated with an antibiotic regimen, and you can usually recover from a case within a week or so.

Read more: Chlamydia »

Genital herpes

  • Symptoms. Symptoms include itching and pain, tiny fluid-filled or red-colored bumps, and ulcers that may eventually leave scabs.
  • Prevalence. As of 2016, around 12 percent of people in the United States have genital herpes.
  • Keep in mind. It’s possible to transmit herpes even if you don’t have sores or symptoms.
  • Treatment. Antiviral medications, such as acyclovir and valacyclovir, can treat outbreaks. However, no cure currently exists for herpes.

Read more: Genital herpes »

Genital warts and human papillomavirus (HPV)

  • Symptoms. Symptoms include small areas of swelling around the penis (in the case of genital warts), cauliflower-shaped warts, and itching around the penis.
  • Prevalence. Around 45 percent of men in the United States currently have human papillomavirus (HPV), which can sometimes cause genital warts. It affects 79 million Americans overall.
  • Keep in mind. There’s currently no recommended HPV test for men and those with a penis.
  • Treatment. Genital warts are usually treated with a medication that’s applied to the warts. However, they can also be removed surgically if medication doesn’t work.

Read more: Human papillomavirus »

Gonorrhea

  • Symptoms. Symptoms include burning during urination, yellow or green discharge, and pain in the testicles.
  • Prevalence. In 2018, there were 341,401 reported cases in men in the United States.
  • Keep in mind. If left untreated, gonorrhea can increase a person’s chances of getting HIV.
  • Treatment. Gonorrhea is usually treated with a regimen of two medications, or dual therapy.

Read more: Gonorrhea »

HIV

  • Symptoms. Symptoms include fever, rash, sore throat, and swollen lymph nodes. Symptoms worsen as HIV progresses.
  • Prevalence. Over 1.2 million people in the United States are currently living with HIV.
  • Keep in mind. HIV is thought to occur more frequently in men who have sex with men because of the additional risk of transmission from anal sex.
  • Treatment. HIV isn’t curable, but it can be treated by several classes of drugs that stop the virus from copying itself and taking over body cells.

Read more: HIV »

Trichomoniasis

  • Symptoms. Symptoms are rare in people with a penis, but they can include itching on the penis, painful urination, and penile discharge.
  • Prevalence. Trich affects over 3.7 million people in the United States.
  • Keep in mind. Around 20 percent of people with trich acquire it again within 3 months of being treated.
  • Treatment. Trich is easy to cure and is usually treated with one dose of antibiotics.

Read more: Trichomoniasis »

STDs can affect anyone who’s sexually active, regardless of their age, race, or sexual orientation. However, many STDs are highly preventable.

Abstinence is the only foolproof method to protect against STDs. However, by being aware of changes in your body and practicing safer sex, you can protect yourself and your partners.

Consistently using condoms and other barrier methods makes transmission less likely.

Learn more: STD prevention »

STDs can be transmitted through vaginal, oral, and anal sex. It’s important to practice safer sex during all sexual activities.

Condoms can be used for vaginal, oral, and anal sex. Dental dams and other barriers can be used for any type of oral sex.

Many people believe that oral sex is risk-free. However, numerous STDs can be transmitted during oral sex, including syphilis, herpes, and gonorrhea.

Some STDs are transmitted more easily during anal sex. These STDs may be more common in men who have sex with men.

No matter your sexual orientation, you should take good care of your sexual health by always having safer sex and being regularly tested for STDs.

Regular testing is a good idea if you’re not in a long-term, mutually monogamous relationship.

Although safer sex is good at reducing STD transmission, it’s not perfect. Regular testing is the best way to take charge of your sexual health.

It’s important to ask your doctor for STD testing. You may assume that your doctor will screen you for STDs at your annual physical exam, but if you don’t ask, you may not be tested.

Even if your doctor does test you, you may not be given every test you want — there aren’t good screening tests for every STD. Ask your doctor at every physical exactly what you’re being tested for and why.

If you suspect you have an STD (and you live in the United States), find a testing center near you. Contact them as soon as you can to avoid any long-term effects of a potential STD diagnosis.

You should request STD tests at every physical, but you should also visit a testing center anytime you’ve had unprotected sex (especially if you believe your partner may have an STD).

Test results are usually available in a few days to a week. Some may require simple urine samples, but others may require blood tests.

Learn more: STD testing: Who should be tested and what’s involved »

While people with a vagina can get a Pap smear and HPV test, there currently isn’t an HPV screening test for those with a penis.

Some types of HPV cause no symptoms, while others cause genital warts. Talk with your doctor if you notice any bumps or warts.

To determine what STD tests you need, talk to your doctor honestly about your sexual risk. Tell your doctor if you think you might have been exposed to an STD or if you’re just coming in for preventive screening.

It’s also good to mention whether you practice receptive anal sex. Anal sex can put you at risk for certain STDs that require special testing. For example, an anal Pap smear can be used to test for signs of HPV-related anal cancers.

Finally, tell your doctor if you reliably practice safer sex for oral, anal, and vaginal sex. This can help your doctor assess your risk.

Complications of STDs can be minor, such as inflammation of the eyes and pain in the pelvic region.

Other complications can be life threatening or otherwise cause lasting harm, such as:

  • heart disease
  • infertility
  • arthritis
  • HPV-related cancers of the cervix and rectum

Treatment for STDs varies based on whether the STD is bacterial or viral.

Bacterial STDs, such as gonorrhea, chlamydia, or syphilis, can be treated with antibiotics. These may include metronidazole or tinidazole (for trichomoniasis).

Viral STDs, such as herpes, must be treated with antiviral drugs. Sometimes these drugs must be taken daily to keep the condition from breaking out again. This is known as suppressive therapy.

HPV cannot be cured completely, but getting vaccinated can help you substantially lower your risk for contracting HPV or an HPV-related STD.

A pre-exposure prophylaxis (PrEP) pill can help you avoid getting HIV if your doctor believes you’re at risk. The pill consists of two drugs that fight HIV if it enters your body and treat any symptoms or complications.

This pill must be taken every day. It can be a successful method of preventing HIV along with other safer sex habits.

Sexually transmitted diseases are more common than you might think.

Whenever you see any symptoms of an STD or believe you may have a risk for transmission, get tested. See your doctor as soon as possible to avoid any pain or discomfort associated with your symptoms.

Be honest with your doctor when describing your sexual history and your symptoms.

Talking about your sex life or getting an STD may feel too personal or uncomfortable to share.

But learning about an STD early, taking preventive measures, and getting treatment quickly will help prevent long-term consequences that affect your health and allow you to enjoy a healthier sex life.