How do STD tests work?

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Sexually transmitted infections (STIs), often called sexually transmitted diseases (STDs), are very common.

According to the Centers for Disease Control and Prevention (CDC), 68 million people were living with STIs in the United States in 2018. It’s likely that many STIs go unreported, so that number is potentially higher.

Many STIs have no symptoms or very nonspecific symptoms, which can make them hard to notice. The stigma around STIs also discourages some people from getting tested.

If left untreated, STIs can cause severe health problems, including cancer and infertility. Testing is the only way to know for sure if you have an STI. In this article, we’ll go over who should get tested, where you can get tested, and other frequently asked questions.

The difference between STDs and STIs is often muddled.

An STD is a sexually transmitted disease resulting from an STI. Infections happen when bacteria, parasites, or viruses enter the body. This process happens before a disease develops.

While STDs stem from infections (STIs), having an STI does not necessarily mean you will develop a disease from that infection.

As we mentioned, some infections may show no symptoms, so testing is very important for preventing the spread of STIs. On the other hand, a disease typically has more clear-cut signs or symptoms.

If you’ve been sexually active, it’s a good idea to be tested for STIs. Also, get tested if:

• you’re about to begin a new relationship
• you and your partner are thinking about not using condoms or other barrier methods of birth control
• your partner has cheated on you
• you or your partner have multiple partners
• you have symptoms that suggest you might have an STI

If you’re in a long-term, mutually monogamous relationship and both you and your partner were tested before entering the relationship, you may not need regular STI testing.

But many people in long-term relationships weren’t tested before they got together. If that’s the case for you and your partner, it’s possible that one or both of you have been living with an undiagnosed STI for years. The safest choice is to get tested.

There are a number of different STIs. To learn which ones you want to get tested for, talk with a doctor. They may encourage you to be tested for one or more of the following:

• chlamydia
• gonorrhea
• HIV
• hepatitis B
• syphilis
• trichomoniasis

Your doctor probably won’t offer to test you for herpes unless you have a known exposure or ask for the test.

Ask your doctor

If you visit a doctor for an annual physical or sexual health checkup, don’t assume that your doctor will automatically test you for all STIs. Many physicians don’t regularly test patients for STIs. It’s important to ask your doctor for STI testing, and ask which tests they plan to do and why.

Taking care of your sexual health is nothing to be shy about. If you’re concerned about a particular infection or symptom, talk with a doctor. The more honest you are, the better treatment you can receive.

It’s important to get tested if you’re pregnant, as STIs can affect the fetus. Your doctor should screen for STIs, among other things, at your first prenatal visit.

Also, it’s important to get tested if you’ve experienced sexual assault or any other type of sexual violence. If you’re a survivor of sexual assault, seek care from a trained healthcare professional.

Organizations like the Rape, Abuse & Incest National Network (RAINN) offer support for survivors of rape or sexual assault. You can call RAINN’s 24/7 national sexual assault hotline at 800-656-4673 for anonymous, confidential help. RAINN can also help you find local support if needed.

Discuss your risk factors

It’s also important to share your sexual health risk factors with your doctor. In particular, always tell them if you have anal sex.

Some anorectal STIs can’t be detected using standard STI tests. Your doctor might recommend an anal Pap smear to screen for precancerous or cancerous cells, which are linked to the human papillomavirus (HPV).

Also, tell your doctor about:

• the types of protection you use during oral, vaginal, and anal sex
• any medications you’re taking
• any known or suspected exposures you’ve had to STIs
• whether you or your partner have other sexual partners

Some places you can go to receive STI testing include:

• Planned Parenthood. STI testing is available at Planned Parenthood. Costs vary by certain factors, including income, demographics, and assistance eligibility.
• Doctor’s office. For quick testing, you can schedule an appointment with a doctor or visit your local urgent care center.
• Local health clinics. Most government-funded healthcare clinics offer free or low cost STI testing for gonorrhea, chlamydia, syphilis, and HIV. Some also receive funding to test for herpes, trichomoniasis, and hepatitis.
• Pharmacy. Some pharmacies offer options to schedule testing for certain STIs, like gonorrhea, chlamydia, syphilis, and HIV.
• At home. Currently, the OraQuick In-Home HIV Test is the only rapid at-home HIV test that’s approved by the Food and Drug Administration (FDA). You have other options if you don’t live in the United States. Other STI home testing kits are also available, like LetsGetChecked, Everlywell, and Nurx.

Several STIs are notifiable diseases. That means your doctor is legally required to report positive results to the government. The government tracks information about STIs to inform public health initiatives. Notifiable STIs include:

• chancroid
• chlamydia
• gonorrhea
• hepatitis
• HIV
• syphilis

First, acknowledge that testing is a responsible choice to make, not only for your health and well-being but for that of your current or future sexual partners. Your decision deserves a pat on the back.

Testing is for everyone, including those with limited sexual history.

Next, remember that testing frequency depends on a number of factors. If you feel uneasy about a sexual encounter you had yesterday and get tested the next day, an infection won’t be detectable yet.

You can talk with a healthcare professional to figure out a screening frequency that makes sense for you. The “window period” for contracting an infection can be as early as 1 week or stretch out as far as several months after the encounter.

If a doctor does your test, remember to be as honest as possible about your history or any risk factors. Holding back details can lead to certain tests being skipped, which could result in undiagnosed STIs.

It’s a good idea to consider any costs that may factor in depending on where or how you choose to get your test. Some testing can be done for no charge or a small amount.

You can also consider telling your partners that you are getting tested — you may even decide to get tested together.

There are no specific instructions you have to follow before getting tested, and it’s fine to be tested while on your period (although this changes if you decide on at-home testing).

Finally, testing can come with some unpleasant nerves. It’s completely normal to feel anxious about testing.

Remember, STIs are treatable and common. Still, waiting on results can be daunting.

If you’d like a chance at hearing your results faster, consider downloading the Healthvana app. This app delivers faster test results, but first check to make sure it’s available in your state and health clinic.

Depending on your sexual history, your doctor may order a variety of tests to check for STIs, including:

Blood and urine tests

Most STIs can be tested by using urine or blood samples. Your doctor can order urine or blood tests to check for:

• gonorrhea
• syphilis
• chlamydia
• HIV

In some cases, urine and blood tests aren’t as accurate as other forms of testing. It may also take a month or longer after being exposed to certain STIs for blood tests to be reliable.

If a person contracts HIV, for example, it can take a couple of weeks to a few months for tests to detect the infection.

Swabs

Many doctors use vaginal, cervical, or urethral swabs to check for STIs.

• If you have a vagina, your doctor can use a cotton applicator to take vaginal and cervical swabs during a pelvic exam.
• If you have a vagina or a penis, they can take urethral swabs by inserting a cotton applicator into your urethra.
• If you have anal sex, they may also take a rectal swab to check for infectious organisms in your rectum.

Pap smears and HPV testing

Strictly speaking, a Pap smear isn’t an STI test. A Pap smear is a test that looks for early signs of cervical or anal cancer.

People assigned female at birth who have persistent HPV infections, particularly infections by HPV 16 and HPV 18, are at an increased risk of developing cervical cancer. People who have anal sex can also develop anal cancer from HPV infections.

A normal Pap smear result says nothing about whether you have an STI. To check for HPV, your doctor will order a separate HPV test.

An abnormal Pap smear result doesn’t necessarily mean that you have or will get cervical or anal cancer. Many abnormal Pap smears resolve without treatment.

If you have an abnormal Pap smear, your doctor may recommend HPV testing. If the HPV test is negative, it’s unlikely that you’ll develop cervical or anal cancer in the near future.

HPV tests alone aren’t very useful for predicting cancer. According to the CDC, about 13 million people in the United States contract HPV each year, and most sexually active people will get at least one type of HPV at some point in their lives. Most of these people never develop cervical or anal cancer.

Physical examination

Doctors can diagnose some STIs, like herpes and genital warts, through a combination of physical examination and other tests.

A doctor can conduct a physical exam to look for sores, bumps, and other signs of STIs. They can also take samples from any questionable areas to send to a laboratory for testing.

It’s important to let a doctor know if you’ve noticed any changes on or around your genitals. If you have anal sex, also let them know about any changes on or around your anus and rectum.

Although some STIs can come without symptoms, it’s still good to watch for any signs of infection, even if they are very mild.

See a doctor or healthcare professional right away if you notice any of these symptoms:

• changes in urination
• strange discharge from the vagina, penis, or anus
• genital itching or burning
• sores, bumps, rashes
• pelvic pain or pain in the lower abdominal region
• unusual vaginal bleeding
• painful penetrative sex

If you get a positive STI test result, it’s important to follow up with your doctor for treatment. Also, make sure you inform any recent sexual partners, as some STIs can be transmitted back and forth. It’s a good idea to consider how you want to tell your partners — while factoring in safety if that’s a concern.

For example, a face-to-face conversation may be no big deal for some partners, while for others, it could pose harm if your partner has a history of emotional or physical aggression.

There are also anonymous, free options for sharing this information with partners if you prefer:

• STDCheck
• TellYourPartner
• Let Them Know
• Health Initiative for Men

These options do not require the use of your personal information.

If you opt for a face-to-face conversation instead, it may be helpful to have relevant research and resources on hand. This way, you can answer any questions and discuss things with your partner, including treatment options, risks, incubation periods, etc.

It’s also OK to feel a wide variety of emotions if you test positive. These feelings are normal, and you can talk with your doctor about any concerns you may have.

How much does STI testing cost?

STI testing costs depend on several factors, like:

• where you get tested
• if you have insurance
• what type of insurance you have
• your income

Because of the Affordable Care Act, many insurance plans offer free or low cost STI testing. There are also other methods of low cost STI testing.

What STIs should I be tested for?

According to CDC guidelines:

• Anyone ages 13 to 64 should be tested for HIV at least once in their life, as well as after any potential exposure.
• Sexually active women under 25 years old should be tested for gonorrhea and chlamydia yearly.
• Women who are 25 years and older with multiple sexual partners or partners with an STD should get tested for gonorrhea and chlamydia yearly.
• Pregnant people should be tested for syphilis, HIV, hepatitis B, and hepatitis C, and high risk pregnant people should be tested for gonorrhea and chlamydia in early pregnancy.
• Sexually active gay men, bisexual men, or other men who have sex with men should be tested for syphilis, chlamydia, HIV, and gonorrhea every 3 to 6 months if they have multiple or anonymous partners.
• Anyone who practices sex that could put them at risk of infection or who shares drug injection equipment should get tested for HIV yearly.

How long does an STI test take?

The length of time it takes for an STI test depends on the type of test. But most STI tests take a few minutes to collect either urine, saliva, or a blood sample.

Some STI results can come back to you as soon as 20 minutes after being tested, while other tests could take up to 1 week for results.

Are STI and STD tests the same?

The terms STI and STD are often used interchangeably, and the two are essentially the same, except STDs are STIs that have symptoms. In short, all STDs started as STIs.

Testing for an STI and STD is the same. However, it’s important to note that STIs have an incubation period. This is the time between when you contract them and when your body recognizes them. So, it’s possible to take a test too early for an STI to be detected.

Can I take an STI test on my period?

According to Planned Parenthood, it’s perfectly OK to get screened for STIs during any day of your menstrual cycle.

Some at-home tests do recommend waiting a few days after your period to test for certain diseases, though, so be sure to check the test instructions if you are using an at-home product.

Can I test myself for STIs?

Some companies offer at-home tests for a wide variety of infections. Online tests are also available for some STIs, but they aren’t always reliable. Check to make sure the FDA has approved any test you buy.

STIs are common, and testing is widely available. The tests can vary depending on which STIs your doctor is checking for.

Talk with a doctor about your sexual history and ask which tests you should get. They can help you understand the potential benefits and risks of different STI tests. They can also recommend appropriate treatment options if you test positive for any STIs.