It’s a scene many know well: you’re lying on your back with a flimsy dressing gown while your doctor tells you to take a deep breath and relax. Although many of us rely on our doctors to let us know when our next pap smear is, a change in provider or a move might shake you from your schedule. However, keeping your pap smears regular can help detect high-risk forms of HPV—the most dangerous of which can lead to cervical cancer.

Pap smears are important tests to stay on top of. Here’s what you need to know.

What is HPV?

HPV is a group of viruses with more than 100 types that can be spread through vaginal, anal, and oral sex. HPV is extremely common, and in the United States, it’s reported by the Centers for Disease Control that nearly all sexually active people are infected with HPV at least once within their lives.

For the most part, HPV causes no problems for the infected and will clear up within a few months. Low-risk types of HPV will not cause disease, although a few low-risk types can cause warts on the genitals, anus, mouth, and throat. According to the World Health Organization, 90% of all infections will clear within two years.

What is the connection between HPV and cervical cancer?

For anyone with a cervix, there is a risk of an HPV infection becoming chronic and leading to cancer. According to the National Cancer Institute, nearly every case of cervical cancer is caused by HPV. Out of the various types of HPV, at least 14 are cancer-causing and categorized as high risk. Two types (16 and 18) cause 70% of cervical cancers and pre-cancerous cervical lesions.

When it comes to cancer diagnoses, one of the biggest factors in staying healthy is early detection—finding cancerous cells before they have had a chance to grow and spread. A pap smear is a screening for high-risk types of HPV and cervical cancer.

What happens during a pap smear?

Whoever is performing the exam—likely a nurse or a doctor—will use a medical instrument known as a speculum. A speculum is a metal tool with a distinct duck bill shape that’s inserted into the vagina. Once it’s opened inside the vagina, it allows your medical practitioner to more clearly see your cervix. Then, they’ll use a small brush or scraper to gently scrape off cells and mucus around your cervix for testing.

Two tests can be done at the doctor’s office:

  • The pap test (or pap smear), which tests for precancerous cells
  • The HPV test, which identifies the presence of HPV

The whole process only takes a few minutes, and most patients describe the sensation as uncomfortable. If you’re nervous about the process, you should talk to your doctor, since muscles tightened from nerves can make the test even more uncomfortable.

What happens after a pap smear?

After a pathologist is able to examine the collected sample, results from the pap smear can take several weeks to come through. Depending on these results, you might be asked to retest in a year or have a colposcopy (an examination of the cervix).

HPV types fall into two groups: low risk and high risk. If a high risk HPV type is found—such as HPV16 or HPV18—the results for the HPV test will come back as positive. If precancerous cells are found in the pap test, early detection of cancer will help to prevent its spread and allow more options for removal and therapy. Your doctor will be able to guide you through this process and create a plan specific to your results.

How often should I get a pap smear?

Because cervical growth has a slower growth rate than some other cancers, doctors recommend the following schedule for pap smears:

  • After the age of 21 and until the age of 30, you should get a pap smear every three years (so long as the results come back normal).
  • Between the ages of 30 and 65 years old, you can prolong the pap smear to every five years.
  • After the age of 65, you will no longer need to be screened as long as your previous tests came back normal or you have had a total hysterectomy for non-cancer related reasons.

Understanding the HPV vaccination

Prior to testing, any child can be vaccinated against HPV after the age of 9, though the CDC recommends it’s started around the ages of 11-12. The vaccine includes two doses, the second of which is given 6-12 months after the first. After your 15th birthday, the vaccine must be done in three doses.

According to the CDC, infections with HPV types that cause most HPV cancers and genital warts have dropped 86% in teen girls since the introduction of the vaccine into the United States.

The Gardasil HPV vaccine is approved for use in people ages 9 to 45, so even if you didn’t get the vaccine as a child, you are still able to as an adult and can consult with your doctor if you’d like to do so. As with any vaccine, side effects can occur, the most common of which include soreness at the injection site, dizziness and fainting, nausea, and headache.