STIs are very common and can come with a variety of symptoms. Although some people might not experience symptoms at all, it’s still worthwhile to know what signs to look out for.

If left untreated, some STIs can cause serious damage to the body and be transmitted to other people through sexual contact.

STI symptoms can range from mild to severe — and they can affect different parts of the body.

After an initial infection, it can take days, weeks, months, or even years for symptoms to appear.

But it’s also common for some STIs, like chlamydia and hepatitis B, to be asymptomatic. This means people may not even realize they have it.

Here are the main symptoms to be aware of:

  • Pain when urinating or having sex can be a sign of everything from chlamydia and gonorrhea to genital herpes.
  • Dark urine can occur with hepatitis B.
  • Unusual discharge from the vagina, penis, or anus can appear with chlamydia, gonorrhea, and trichomoniasis.
  • Itchiness around the genitals may be seen with the likes of genital herpes and pubic lice.
  • Bleeding between periods or after sex is one of the most common chlamydia symptoms.
  • Pelvic and testicular pain can also occur with chlamydia.
  • Joint and muscle pain can also occur with hepatitis B.
  • Small blisters or sores around the genitals are potential symptoms of syphilis and genital herpes.

Even flu-like symptoms and rashes can be associated with STIs like HIV and syphilis.

On that note, it’s important to realize that most of these can be symptoms of other conditions and can also easily be mistaken for other health concerns.

Consult with a doctor or other healthcare professional if you suspect that you’ve been exposed to an STI.

STDs vs. STIs

Did you know there’s a difference between an STI and a sexually transmitted disease (STD)?

STDs always begin as an STI. The initial infection occurs when bacteria, viruses, or parasites infiltrate the body.

A STI can become a disease if the foreign bodies begin to disrupt normal processes —this usually means symptoms start appearing.

Examples of STDs include pelvic inflammatory disease (PID), which results from an untreated chlamydia or gonorrhea infection, and cervical cancer, which can be caused by the human papillomavirus (HPV).

Remember, not all STIs will become an STD, even if they are left untreated.

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The major causes of STIs are:

  • bacteria, such as chlamydia or syphilis
  • viruses, such as HPV or HIV
  • parasites, such as Trichomonas vaginalis

These causes are primarily transmitted through bodily fluids during sexual activity. This includes vaginal, oral, and anal sex.

But some can be transmitted from person to person via skin contact — for example, if you touch your partner’s genitals with yours.

Although anyone can contract an STI, data shows that young people and men who have sex with men (MSM) are at the greatest risk.

On the whole, an infection is classed as an STI if it’s mainly transmitted through sexual contact.

However, there are a few exceptions. For example, cytomegalovirus (CMV) can be transmitted through sexual activity, but it’s not considered an STI as it can be transmitted in a number of other ways, too.

Some STIs are much more common than others. HPV is the most common STI in the United States, with chlamydia and gonorrhea also heavily reported.

Other common STIs include genital herpes, with more than 1 in 6 people ages 14 to 49 developing it, according to the Centers for Disease Control and Prevention (CDC).

Syphilis is much rarer, but there has been a resurgence in cases in recent years, primarily among MSM.

HIV infections, on the other hand, have greatly declined since the 1980s, with almost 35,000 new cases occurring in the United States in 2019.

If treated promptly, most STIs are unlikely to become an STD. However, if left untreated for some time, the risk of an STD becomes greater.

Not all STIs can be cured. HPV is one example. Some HPV strains can lead to cancer, so getting regularly screened for abnormal cell changes is key to early diagnosis.

A doctor or other healthcare professional can perform tests and examinations to help figure out whether you have an STI or a different condition altogether.

These may include:

  • rapid fingerprick tests
  • fluid samples from the vagina, penis, anus, or any sores that have appeared
  • blood tests
  • urine samples
  • pelvic and physical examinations

It’s important to get tested regularly if you are sexually active and to consult a healthcare professional as soon as you develop any symptoms.

Early diagnosis means you can get treatment earlier and decrease the risk of complications.

In some cases, untreated STIs can lead to serious health problems.

They can:

  • increase the risk of infertility
  • cause certain types of cancer
  • make a person more susceptible to contracting HIV
  • lead to organ damage and even death

Pregnant people should be aware that STIs can affect an unborn baby and the overall pregnancy, too.

Some STIs can be passed to the baby before and during birth, potentially leading to:

  • infections
  • pneumonia
  • meningitis
  • blindness
  • deafness
  • brain damage
  • stillbirth

Premature labor is also a risk of having an untreated STI.

This is further complicated as some treatments may not be safe during pregnancy. A doctor or other healthcare professional will be able to recommend a treatment and delivery plan that will reduce the risk to you and your baby.

As some STIs are asymptomatic, all of the above makes it even more important to get screened on a regular basis.

Doctors can treat certain STIs:

  • Chlamydia and trichomoniasis are cured with antibiotics.
  • Gonorrhea can be cured with antibiotics. However, some drug-resistant strains of the bacteria have emerged that don’t respond to traditional treatments and may be more difficult to cure.
  • Syphilis can also be cured with antibiotics. The medication your clinician chooses depends on the stage of syphilis.
  • Acute hepatitis B usually doesn’t require treatment. If the virus doesn’t clear on its own, antiviral medications are used to treat chronic hepatitis B.

Some conditions aren’t curable, but treatments can help reduce their symptoms. Herpes, HPV, and HIV fall into this category.

For herpes, clinicians will prescribe medications known as antivirals to shorten an outbreak. Some people take these medications on a daily basis to help reduce the likelihood of an outbreak.

Daily antivirals are also used to treat HIV and stop the virus from replicating in the body. Within 6 months of treatment, the virus will become undetectable in most people.

Clinicians don’t have specific treatments for genital warts caused by HPV. However, they may prescribe topical medications or perform procedures to help shrink or remove the lesions.

Remember that even if you’ve been treated and no longer have an STI, you can contract the STI again.

The only 100 percent effective way to prevent STIs is to abstain from any sexual activity.

But there are ways to reduce the risk of both contracting an STI and developing complications:

  • Use condoms and other barrier methods correctly to reduce the risk of coming into contact with bodily fluids.
  • Get tested regularly and encourage partners to as well. Note that STI screening isn’t a part of a standard health exam, so it’s important to ask for specific testing to get your results.
  • Have open conversations with sexual partners about your sexual history and test results.
  • Consider getting vaccinated against hepatitis B and HPV.
  • If you’re at a higher risk of contracting HIV, speak with a healthcare professional about a preventive treatment called pre-exposure prophylaxis (PrEP).

Most STIs can be treated, if not cured. The key is prevention where possible and regular screening to ensure that any infections are promptly treated.

If you experience any symptoms, no matter how minor, it’s important to seek medical advice from a qualified healthcare professional.


Lauren Sharkey is a U.K.-based journalist and author specializing in women’s issues. When she isn’t trying to discover a way to banish migraines, she can be found uncovering the answers to your lurking health questions. She has also written a book profiling young female activists across the globe and is currently building a community of such resisters. Catch her on Twitter.