Sexually Transmitted Infections (STIs): A Guide to Testing
Key takeaways:
Anyone who is sexually active should regularly get tested for common STIs — especially people with new or multiple partners.
Many common sexually transmitted infections (STIs) do not cause any symptoms. So testing is important to prevent health complications from infection and spreading the disease.
It helps to know the symptoms of different STIs, as well as the ones you are at risk for. That way, you know which tests to ask for when you see your provider.
Table of contents
If you are sexually active, especially with new or multiple partners, you may be wondering if you should be tested for any sexually transmitted infections (STIs). And if you need to be tested, which tests should you get?
We’ll go through the most common sexually transmitted infections so you know if and when you should be tested.
Quiz: Do you have a UTI or a STD/STI?
Chlamydia
Chlamydia is caused by the bacteria Chlamydia trachomatis. It is the most common STI.
What are the symptoms? You may not have any symptoms with chlamydia. If you do, they can include:
Pain with urination
Pain in the lower abdomen or pelvic area
Abnormal discharge from the vagina or tip of the penis
Rectal pain
Throat pain (sometimes chlamydia can infect the throat)
Who should get tested? Anyone sexually active should be tested for chlamydia, but especially:
Women under 25 years old
Women with new or multiple sexual partners
Men who have sex with men
Anyone with a partner who tests positive for any STI
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How often should you get tested? At least once a year. If you have new or multiple partners, you can get tested as frequently as every 3 to 4 months.
How is the test done? Testing for chlamydia can be done with a swab inside the vagina or penis. It can also be done with a test on a urine sample.
Gonorrhea
Gonorrhea is caused by a bacteria called Neisseria gonorrhoeae. It is the second-most common STI. And it has a lot of the same symptoms and testing guidelines as chlamydia.
What are the symptoms? Many people — both males and females — do not have symptoms with a gonorrhea infection. If you do, they may be mild and can include:
Pain with urination
Discharge from the vagina or tip of the penis
Frequent urination
Vaginal bleeding or spotting
More severe symptoms can include fever, vomiting, and abdominal pain.
Who should get tested? Anyone sexually active should be tested for gonorrhea, especially:
Women under 25 years old
Women with new or multiple sex partners
Men who have sex with men
Anyone with a partner who tests positive for any STI
How often should you get tested? At least once a year. If you have new or multiple partners, you can get tested as frequently as every 3 to 4 months.
How is the test done? This test can be done by a swab inside the vagina or penis, or by testing urine.
Herpes
Herpes is caused by the viruses HSV-1 and HSV-2. Once you are infected with herpes, the virus lives in your body long term. It can then cause breakouts from time to time.
What are the symptoms? The classic symptom of a herpes infection is painful blisters. These can show up in someone’s mouth, rectum, or genital area. After the initial infection, most people continue to have breakouts throughout their life. The frequency and severity of these breakouts differs from person to person. In between breakouts, you will not have symptoms.
Who should get tested? You should get tested if:
You have blisters in your genital area.
Your sexual partner has genital herpes.
You are pregnant and may have had or been exposed to herpes in the past.
How often should you get tested? There are no specific guidelines as to how often you should get tested. But it’s a good idea to get tested anytime you have unprotected sex and do not know the herpes status of your partner.
How is the test done? If you have any blisters, they can be swabbed for herpes. If you have no blisters at the time of testing, you can also check for herpes with a blood test.
HPV
HPV (human papillomavirus) is actually a group of viruses. This STI can cause genital warts. But it is better known for the way it can increase the risk of certain types of cancers — like cervical cancer, rectal cancer, and throat cancer.
Most people — even those who only have one lifetime sexual partner — have likely come in contact with HPV. In most cases, your immune system gets rid of the virus over time.
What are the symptoms? The majority of people with HPV do not have any symptoms. A small percentage of people with HPV will develop genital warts, which will look like bumps on your genital or anal area. Some people may have bleeding with intercourse or spotting between periods. But most people do not realize they have it until they are tested for it.
Who should get tested? You should be tested if you have new bumps in the anal or genital area or had unprotected sex with someone who has HPV.
Women are routinely screened with a pap smear every 3 years as part of their annual checkups. Pap smears check the cervix for abnormal cells that can be a sign of an HPV infection.
Anal pap smears can also check for abnormal cells. You should consider an anal pap smear if you have:
Regular anal intercourse
A history of HPV infections
An abnormal anal pap smear
A weakened immune system
How often should you get tested? The guidelines are more clear for pap smears than for HPV alone. Most women should have a pap smear every 3 years. But this can vary based on your age, current risk, and history of abnormal pap smears in the past. It is important to work with your provider to figure out the right schedule of testing based on your circumstances
How is the test done? If you have any bumps on your genital area, they can be removed and looked at under a microscope. Pap smears of the cervix and anus are performed with a swab of the area.
HIV
HIV (human immunodeficiency virus) is a virus that infects the cells of your immune system. It is a life-long condition, but early detection and treatment can keep the virus well controlled.
What are the symptoms? Many people do not have any symptoms with HIV. Others may develop a flu-like illness when they are first infected, which then goes away. This can feel similar to many other viruses out there, so it can be difficult to know if you have HIV.
Who should get tested? The CDC recommends everyone between the ages of 13 and 64 be tested at least once. But you may need more than one test in your lifetime based on certain conditions.
How often should you get tested? If you’re sexually active, you should be tested at least once. But certain people should be tested more often than that:
If you become pregnant, you should be checked for HIV with each pregnancy.
Anytime you may have a potential exposure to HIV, you should be tested.
Men who are sexually active with other men should be tested once a year. If you have different partners, you may consider testing as often as every 3 to 6 months.
Anyone who uses intravenous drugs should be tested once a year.
How is the test done? HIV is detected by a blood test.
Syphilis
Syphilis is caused by a bacteria called Treponema pallidum. The number of syphilis cases is rising each year.
What are the symptoms? When someone is first infected with syphilis, they sometimes develop a painless ulcer in their genital area that can last several weeks. Because it does not hurt, it is easy to overlook.
If untreated, syphilis can progress. In the secondary phase, you may develop a rash and feel under the weather. Afterwards there can be a long period without symptoms. A third (tertiary) phase can also happen up to 20 or 30 years later. In this phase, the infection can be severe and spread throughout the body to the heart and brain.
Who should get tested? The CDC recommends the following people be tested:
Pregnant women
Men who have sex with other men
Anyone with a potential exposure to syphilis
How often should you get tested? The CDC recommends that men who have sex with other men should be tested at least once a year. If they have new or multiple partners, testing should occur as often as every 3 months. Pregnant women are tested with each pregnancy.
How is the test done? If someone has an ulcer, this can be swabbed and looked at under a microscope. Once the ulcer has disappeared, a blood test is the best way to test for syphilis.
Hepatitis
Hepatitis is a medical term that refers to any inflammation of the liver. Several viruses can cause hepatitis. Some of these viruses can be sexually transmitted, most commonly hepatitis B. Hepatitis A and hepatitis C can also be transmitted sexually.
What are the symptoms? Many people do not have symptoms and do not know they have hepatitis. If you do have symptoms, they can include:
Fever
Nausea and vomiting
Abdominal pain
Yellowing skin, called jaundice
Who should get tested? Everyone over 18 should be tested at least once. Testing is also recommended for:
Pregnant women
People who have HIV
People who use intravenous drugs
Men who have sex with other men
How often should you get tested? Pregnant women should be tested with each pregnancy. People with HIV should be tested once a year. People who are at higher risk for hepatitis (such as men who have sex with other men and people who use intravenous drugs) should be tested more frequently, but there are no specific guidelines as to how often.
How is the test done? Hepatitis is diagnosed with a blood test.
Trichomoniasis
Trichomoniasis is caused by a parasite called Trichomonas vaginalis.
What are the symptoms? Many people do not have symptoms, which means their infection can go untreated for years. If symptoms are present, women can experience pain with urination or vaginal discharge. Men can have pain with urination, or pain in their testicles or prostate.
Who should get tested? There are no guidelines for who should be tested. However, anyone experiencing abnormal vaginal discharge should be tested.
How often should you get tested? There are no guidelines for how often people should be tested for trichomonas. Rates of infection can vary by area. If you live in an area with a high rate of trichomonas, your provider may recommend annual testing.
How is the test done? Trichomonas can be detected in:
A urine sample
Vaginal or cervical swabs in women
Urethral swabs in men
Bacterial vaginosis
Bacterial vaginosis (BV) is a condition most often seen in sexually active women. Normally, there is a delicate balance of different types of bacteria in the vagina. BV can develop when that balance gets thrown off.
What are the symptoms? The most common symptom is a gray or whitish, watery vaginal discharge. It tends to have a fishy odor. Some women may also have itching and burning in the vaginal area. But many women have no symptoms.
Who should get tested? You should be tested for BV if:
You are having any of the above symptoms.
You are pregnant.
If you have a vagina and a partner diagnosed with BV.
How often should you get tested? You should be tested as often as you have symptoms, and with each pregnancy.
How is the test done? BV is diagnosed by a vaginal swab.
The bottom line
Many people have a sexually transmitted infection without any symptoms. Other times, the symptoms may be vague or mild.
If you are sexually active, especially with new or multiple partners, it is important to be proactive about STI testing. Don’t be afraid to discuss your sexual practices with your healthcare provider, and ask what testing you need. Early detection is key to getting treatment and preventing the spread of these infections.
Why trust our experts?
References
Centers for Disease Control and Prevention. (2020). Sexual transmission and viral hepatitis.
Centers for Disease Control and Prevention. (2020). What is viral hepatitis?
Centers for Disease Control and Prevention. (2021). Which STD tests should I get?
Centers for Disease Control and Prevention. (2022). Trichomoniasis.
HIV.gov. (2022). Hepatitis B & C.
McCormack, D., et al. (2019). Sexually transmitted infections. Emergency Medicine Clinics of North America.
MedlinePlus. (2020). Herpes (HSV) test.
