Sexual Health: The Complete Guide

Key numbers at a glance

What sexual health covers

Sexual health is much broader than avoiding infections. It includes being able to choose whether and when to have children, enjoying sex without pain or fear, having relationships built on consent and respect, and getting accurate information and care without judgment. It matters at every stage of adult life, from the first sexual relationships of the teen years to the changes that come with menopause and later life.

Two facts shape most of the advice in this guide. First, many sexually transmitted infections cause no symptoms, so testing rather than waiting for symptoms is what finds them before they cause harm. Second, the most effective ways of preventing pregnancy and HIV are often not the ones people know best, so it pays to know the full range of options. In both cases, good information turns a source of worry into a set of manageable choices.

Sexual health is also an area where embarrassment keeps people from asking questions. Clinicians who work in it have heard every question many times, and confidential, low-cost care is widely available in the US, including for people without insurance. The aim of this guide is to explain how things work, what US guidelines recommend and why, and where to go for help.

Sexually transmitted infections: the basics

Sexually transmitted infections, or STIs, are passed on through vaginal, anal or oral sex and, for some, through close skin-to-skin genital contact. Some are caused by bacteria, such as chlamydia, gonorrhea and syphilis, and can be cured with antibiotics. Others are caused by viruses, such as HIV, herpes, hepatitis B and human papillomavirus (HPV); these can be treated, controlled or prevented with vaccines, but most cannot be cured. Trichomoniasis, caused by a parasite, is also common and curable.

Chlamydia is the most commonly reported bacterial STI in the US. Most chlamydia causes no symptoms at all, and the same is often true of gonorrhea, especially in women. Untreated, both can spread to the uterus and fallopian tubes and cause pelvic inflammatory disease, which can lead to long-term pelvic pain, ectopic pregnancy and infertility. In men they can cause painful inflammation of the testicles. Syphilis cases, including syphilis passed on during pregnancy, have risen sharply in the US in recent years, and untreated syphilis can affect the brain, eyes and other organs.

When symptoms do occur, they can include unusual discharge from the vagina, penis or anus, pain when urinating, pain during sex, bleeding between periods or after sex, sores, blisters or warts on or around the genitals, and pain or swelling in the testicles. Any of these is a reason to get tested promptly, but the absence of symptoms is not a reason to skip testing.

Reducing your risk

Condoms, used correctly every time, greatly reduce the risk of most STIs and of HIV, though they protect less well against infections spread by skin contact, such as herpes and HPV. Use latex or polyurethane condoms, put them on before any genital contact, and use water-based or silicone-based lubricant, since oil-based products can weaken latex. Dental dams can be used for oral sex. Vaccination against HPV and hepatitis B, regular testing, fewer partners and talking openly with partners about testing all lower risk further.

Testing: who, when and how

Because so many STIs are silent, US guidelines recommend routine screening for certain groups. The US Preventive Services Task Force recommends screening for chlamydia and gonorrhea in all sexually active women aged 24 and younger and in older women at increased risk, for example those with a new partner, more than one partner, or a partner with an STI. The CDC recommends that everyone aged 13 to 64 be tested for HIV at least once as part of routine health care, and more often for people at higher risk. Pregnant people are screened for HIV, syphilis and hepatitis B early in pregnancy, because treatment protects the baby.

Other groups benefit from more frequent testing. The CDC's treatment guidelines recommend at least yearly testing for HIV, syphilis, chlamydia and gonorrhea for sexually active gay, bisexual and other men who have sex with men, with testing every 3 to 6 months for those at higher risk, including at the sites they have sex with, such as the throat and rectum. Anyone with a new partner, multiple partners or a partner who has an STI should consider testing. Ask your doctor about hepatitis B vaccination and hepatitis C testing as well.

Testing is usually simple: a urine sample, a swab you can often take yourself, or a blood test. There is no single test for all STIs, and a routine checkup or Pap test does not automatically include them, so ask specifically what you are being tested for. Some infections take time to show up on tests after exposure, so your clinician may suggest repeating a test later. At-home and mail-in testing options are also available; ask your doctor or local clinic which are reliable.

• Test before starting a new sexual relationship, ideally both partners
• Ask exactly which infections the test covers
• Get tested promptly for any symptoms, even if you tested recently
• Retest after treatment if your clinician advises, as reinfection is common

Treatment and telling partners

Bacterial STIs such as chlamydia, gonorrhea and syphilis are cured with antibiotics, usually a short course of pills or a single injection. Take the full course exactly as prescribed, do not share medicine, and avoid sex for as long as your clinician advises, usually until you and your partners have finished treatment and symptoms have gone. Gonorrhea has become resistant to many antibiotics over the years, which is why current guidelines specify particular treatments and why buying antibiotics online without a diagnosis is a bad idea.

Viral infections are managed rather than cured. Antiviral medicines can shorten herpes outbreaks, reduce how often they happen and lower the chance of passing herpes on. Hepatitis B can be monitored and treated when needed. Most HPV infections clear on their own within a couple of years, while genital warts can be treated if they bother you. Effective HIV treatment is discussed in the next section.

Telling partners can feel daunting, but it protects their health and prevents you from being reinfected. Your clinician can help you plan what to say. Health departments can notify partners anonymously, without naming you. In nearly all states, clinicians can also give you medicine or a prescription to pass on to your partner for chlamydia or gonorrhea without them needing a separate visit, an approach called expedited partner therapy.

HIV: testing, prevention and treatment

HIV is a virus that attacks the immune system. Without treatment it gradually weakens the body's defenses, eventually leading to AIDS. With treatment, HIV is now a manageable long-term condition, and people who are diagnosed early and stay on treatment can expect a life expectancy close to that of the general population. Some people have a flu-like illness with fever, rash and swollen glands a few weeks after infection, but many have no symptoms for years, so testing is the only way to know.

Treatment has also transformed prevention. HIV medicines taken every day can reduce the amount of virus in the blood to levels so low that standard tests cannot detect it. People with HIV who reach and keep an undetectable viral load do not pass HIV on to sexual partners, a principle summarized as undetectable equals untransmittable, or U=U. Starting treatment soon after diagnosis protects both your health and your partners. Treatment is usually one pill a day, or for some people a long-acting injection, with regular blood tests to check that the virus stays suppressed. People living with HIV can have relationships, sex and children without passing the virus on, and stigma, not the virus, is often the hardest part.

For people without HIV, two medical tools prevent infection. Pre-exposure prophylaxis, or PrEP, is medicine taken before possible exposure, as a daily pill or as a long-acting injection, and is very effective when taken as prescribed. The US Preventive Services Task Force recommends PrEP for people at increased risk of HIV, and most insurance plans must cover it without cost sharing. Post-exposure prophylaxis, or PEP, is a 28-day course of medicine started after a possible exposure, such as condomless sex with a partner of unknown status, a condom breaking, sexual assault or sharing needles. PEP must be started within 72 hours, and the sooner the better.

• Ask your doctor or a sexual health clinic about PrEP if you are at ongoing risk
• Go to an emergency room or urgent care right away after a possible exposure to ask about PEP
• If you have HIV, staying on treatment protects your health and your partners
• Test regularly if you are at risk; testing is confidential

HPV, vaccination and cervical screening

Human papillomavirus is so common that most sexually active people will have it at some point, usually without knowing. Most infections clear on their own. Some high-risk types, however, can persist and cause changes that may lead to cancers of the cervix, anus, penis, vulva, vagina and throat. Almost all cervical cancer is caused by HPV, which is why the vaccine and cervical screening work together to prevent it. There is no routine HPV test for men, and an HPV diagnosis in a long-term relationship does not mean anyone has been unfaithful, because the virus can stay silent for years before it is detected.

The HPV vaccine is recommended at ages 11 to 12 for all genders and can be started at 9. Catch-up vaccination is recommended through age 26 for anyone not fully vaccinated. Some adults aged 27 to 45 may benefit, and this is a decision to make with your doctor, because the vaccine works best before any exposure. The vaccine is most effective when given well before a person becomes sexually active, which is why it is recommended in the preteen years.

Cervical screening finds cell changes before they turn into cancer, so it prevents cancer rather than only detecting it. The US Preventive Services Task Force recommends screening for women and people with a cervix aged 21 to 65. From 21 to 29, a Pap test every 3 years is recommended. From 30 to 65, the options are an HPV test every 5 years, a Pap test every 3 years, or both together every 5 years. Vaccination does not remove the need for screening, and you should keep up with screening even if you are not currently sexually active.

Making screening easier

If you find the exam uncomfortable or distressing, say so. You can ask for a smaller speculum, more time, a chaperone, or to insert the speculum yourself. Avoid booking during a heavy period. Tell your clinician about any past trauma if you feel able to, so they can adapt the exam. Remember that screening is for people without symptoms: bleeding after sex, between periods or after menopause, or persistent pelvic pain, needs a doctor's visit regardless of when you were last screened.

Contraception: finding the right method

There is no single best method of contraception, only the method that best fits your body, health, relationships and plans. Options include long-acting reversible contraception (the implant and hormonal or copper IUDs), the injection, the pill, the patch, the vaginal ring, condoms, diaphragms, fertility awareness methods, and permanent methods such as tubal surgery and vasectomy. Since 2023 a progestin-only birth control pill has been available over the counter without a prescription.

The key thing to understand is the difference between perfect use and typical use. For methods that depend on remembering something, such as the pill, patch, ring or condoms, the pregnancy rate in real life is noticeably higher than with perfect use, because doses get missed and condoms are not always used. The implant and IUDs do not depend on remembering anything once in place, so typical use and perfect use are almost the same. That is why they are the most effective reversible methods, and why the American College of Obstetricians and Gynecologists encourages clinicians to offer them, including to teens and to people who have never been pregnant.

Health matters too. The CDC's US Medical Eligibility Criteria for Contraceptive Use help clinicians match methods to medical conditions. Methods containing estrogen, such as the combined pill, patch and ring, slightly raise the risk of blood clots and are generally not advised for people who have migraine with aura, who smoke and are over 35, or who have certain heart and blood clotting conditions. Progestin-only and non-hormonal methods are usually suitable instead. Tell your clinician about your full medical history and any medicines you take, as some interact with hormonal contraception.

Only condoms protect against STIs, so using condoms alongside another method gives protection against both pregnancy and infection. Contraception is still needed until menopause is confirmed, even if periods become irregular in your forties, so talk to your doctor about when it is safe to stop. It is also worth reviewing your method whenever your circumstances change, such as a new relationship, a new medical condition, a new medicine, or plans for a pregnancy in the next year or two, since the best choice at 20 may not be the best choice at 40.

Emergency contraception

Emergency contraception can prevent pregnancy after unprotected sex or a contraceptive failure, and every option works better the sooner it is used. Levonorgestrel pills are sold over the counter at pharmacies with no prescription or age limit and are most effective within 3 days. Ulipristal acetate, available by prescription, can be used up to 5 days after sex and stays effective for longer. A copper IUD inserted within 5 days is the most effective option and then continues as ongoing contraception. Levonorgestrel may work less well in people with a higher body weight, so ask a pharmacist or clinician which option suits you. Emergency contraception does not end an existing pregnancy.

Periods, fertility and planning a pregnancy

Knowing what is normal for your own body makes changes easier to spot. In adults, a menstrual cycle typically lasts 21 to 35 days, counted from the first day of one period to the first day of the next, and bleeding typically lasts up to 7 days. Tracking cycle length, bleeding days, pain, heavy flow and clots for at least three cycles turns a vague sense that something is wrong into a pattern your doctor can act on. Cycles that are shorter than 21 days or longer than 35, bleeding that lasts longer than 7 days, bleeding between periods or after sex, and periods that suddenly become much heavier or more painful are all worth a doctor's visit.

If you are trying to conceive, the fertile window is roughly the six days ending on the day of ovulation. Rather than timing sex narrowly, which adds stress and little benefit, regular sex every two to three days through the cycle covers the window. Start a daily folic acid supplement of 400 mcg when you begin trying, rather than waiting for a positive test, because it helps prevent serious birth defects of the brain and spine that develop very early in pregnancy. Stopping smoking and cutting down on alcohol help both partners.

Most couples conceive within a year. The American College of Obstetricians and Gynecologists advises an evaluation after 1 year of trying, or after 6 months if the woman is 35 or older, and sooner for women over 40 or for anyone with irregular or absent periods, known endometriosis or pelvic infection, previous cancer treatment, or known sperm problems. Male factors are involved in a substantial share of cases, so both partners should be assessed together from the start.

Sexual function and pleasure

Difficulties with desire, arousal, orgasm or pain during sex are common in all genders and at all ages, but rarely raised in appointments. They often have a physical or medicine-related cause that can be fixed. Antidepressants are a very common and often reversible cause; other contributors include blood pressure medicines, hormonal changes, diabetes, depression, anxiety, tiredness, alcohol, relationship strain and past trauma. Raising the problem with your doctor is the first step, and a medicine review alone sometimes solves it. Do not stop antidepressants abruptly because of sexual side effects; ask about alternatives.

Erectile dysfunction becomes more common with age and can be an early warning sign of heart disease or diabetes, because the small blood vessels of the penis are affected early. New erectile problems are therefore worth a checkup that includes blood pressure, blood sugar and cholesterol. Prescription medicines called PDE5 inhibitors, such as sildenafil, help many men, but they must never be taken with nitrate medicines for chest pain, such as nitroglycerin, because the combination can cause a dangerous fall in blood pressure. Get emergency care for an erection that lasts for hours and will not go down.

Painful sex is never something to simply put up with. It can be caused by infections, skin conditions, endometriosis, pelvic floor muscle tension, vaginal dryness after childbirth or menopause, and other treatable problems. Vaginal dryness and discomfort around menopause, part of what clinicians call the genitourinary syndrome of menopause, often respond well to vaginal moisturizers, lubricants and low-dose vaginal estrogen. A pelvic floor physical therapist or a sex therapist can help too.

• Avoid sexual enhancement products sold online or in gas stations; the FDA has found many contain hidden prescription drugs
• Look at sleep, alcohol, smoking and activity, all of which affect sexual function
• Ask your doctor about a referral to a sex therapist or couples counselor

Consent, healthy relationships and sexual violence

Consent means freely given, informed and ongoing agreement to sexual activity. It can be withdrawn at any time, it applies to each activity and each occasion rather than once for all, and silence or passivity is not agreement. Someone who is asleep, unconscious, or incapacitated by alcohol or drugs cannot consent. The age of consent is set by each state and ranges from 16 to 18. Checking in with a partner is not awkward; it is part of good sex.

Healthy relationships involve respect, honesty and the freedom to make your own choices. Warning signs of an abusive relationship include a partner who controls your money, phone or contact with friends, monitors where you go, pressures you into sex or into not using contraception, or makes you afraid. Abuse does not have to be physical to be serious. The National Domestic Violence Hotline is available 24 hours a day at 1-800-799-7233, or by texting START to 88788.

If you have been sexually assaulted, you can go to a hospital emergency room for medical care, emergency contraception, PEP for HIV, treatment to prevent other infections, and a forensic medical exam if you want one, whether or not you decide to report to police. Many hospitals have specially trained nurses for this. PEP must be started within 72 hours, so try to get care as soon as you can. The National Sexual Assault Hotline, 1-800-656-4673, offers free, confidential support at any hour. Call 911 if you are in danger.

Sexual health in later life

Many people stay sexually active well into later life, but advice and services often overlook them. STI rates in older adults have risen in recent years, partly because people re-entering dating after divorce or bereavement may not think of themselves as at risk and may not have used condoms for decades, and partly because clinicians rarely offer testing unprompted. Use condoms with new partners at any age, and ask for STI testing if you have a new partner. Medicare covers STI screening and counseling for people at increased risk.

Physical changes can affect sex in later life: vaginal dryness and thinning after menopause, erectile changes, arthritis and chronic pain, and the side effects of medicines. Most can be eased, with lubricants, vaginal estrogen, different positions, timing pain relief, or adjusting medicines. Talking openly with a partner and with your doctor makes a real difference. Any bleeding after menopause always needs investigation, and chest pain during or after sex needs a call to 911.

Getting care, costs and talking to your doctor

Confidential sexual health care is available in many places: your primary care doctor or gynecologist, local health department clinics, family planning clinics funded through the federal Title X program, community health centers, and Planned Parenthood health centers. Many offer free or low-cost care with fees on a sliding scale by income, and most do not need a referral. Under the Affordable Care Act, most insurance plans must cover recommended STI screening, HIV PrEP and FDA-approved contraception without a copay when you use an in-network provider. Medicaid also covers family planning services.

Teens can usually get confidential care for STI testing and treatment, and in many states for contraception, without a parent's permission, though the rules vary by state. Ask the clinic about its confidentiality policy, including how insurance statements are handled if you are on a parent's plan. Clinicians will still act to protect a young person who is at serious risk of harm, and they can help a teen think through how to involve a trusted adult if they want to.

To make the most of a visit, be specific: say what symptoms you have, what kind of sex you have and with whom, and what you want, whether that is testing, contraception, PrEP or help with a sexual problem. Clinicians ask about these things to work out which tests and options apply to you, not to judge. If you feel judged or brushed off, you are entitled to see someone else.

• Every year: STI testing if you are under 25 and sexually active, or have a new or more than one partner
• At least once: an HIV test; more often if you are at increased risk
• On schedule: cervical screening from 21 to 65 at the interval your doctor recommends
• Before trying to conceive: start folic acid and review medicines and vaccines
• Whenever things change: review your contraception with a new partner, new medicines or new health conditions

Every guide in this topic

• Sexually Transmitted Infections: What Published Guidance Supports
• The Evidence on Contraception Choices, Without the Hype
• What the Guidance Really Says About HIV
• What the Guidance Really Says About Cervical Screening and HPV
• What the Guidance Really Says About Sexual Function
• Sexual Health Services: What Published Guidance Supports
• Menstrual Cycle Tracking: What Published Guidance Supports
• The Evidence on Fertility Awareness, Without the Hype
• Consent and Healthy Relationships: What the Evidence Actually Says
• The Evidence on Sexual Health in Later Life, Without the Hype

Frequently asked questions

Can I have an STI without any symptoms?

Yes, and it is very common. Most chlamydia causes no symptoms, and gonorrhea, syphilis, herpes, HPV and HIV can all go unnoticed for long periods. Untreated, some can cause infertility, long-term pain or serious illness, and they can be passed to partners. That is why US guidelines recommend regular testing for certain groups rather than waiting for symptoms.

How often should I get tested for STIs?

It depends on your age and risk. Sexually active women 24 and younger should be tested for chlamydia and gonorrhea every year, as should older women at increased risk. Everyone aged 13 to 64 should have an HIV test at least once. Gay and bisexual men are advised to test at least yearly, and every 3 to 6 months if at higher risk. Test whenever you have a new partner or symptoms.

Does a Pap test check for STIs?

No. A Pap test looks for cell changes on the cervix, and an HPV test checks for high-risk HPV types, but neither tests for chlamydia, gonorrhea, syphilis, herpes or HIV. If you want STI testing, ask for it specifically and ask which infections are included. Many STI tests use a simple urine sample or a swab you can take yourself.

What is the difference between PrEP and PEP?

PrEP, or pre-exposure prophylaxis, is taken before possible exposure to HIV, as a daily pill or long-acting injection, by people at ongoing risk. PEP, or post-exposure prophylaxis, is a 28-day course started after a single possible exposure. PEP must begin within 72 hours, and the sooner the better, so go to an emergency room or urgent care right away.

Where can I get emergency contraception?

Levonorgestrel emergency contraception pills are sold over the counter at pharmacies with no prescription or age limit, and work best within 3 days. Ulipristal acetate needs a prescription and works up to 5 days after sex. A copper IUD fitted within 5 days is the most effective option. Whatever you choose, use it as soon as possible after unprotected sex.

Which birth control method is the most effective?

The implant and IUDs, both hormonal and copper, are the most effective reversible methods, because once in place they do not depend on remembering anything. Pills, patches, rings and condoms work well with perfect use but fail more often in real life. The best method is the one that suits your health and life. Use condoms as well if you need protection from STIs.

Do I still need cervical screening if I had the HPV vaccine?

Yes. The vaccine protects against the HPV types that cause most cervical cancers, but not all of them, and it may not protect against an infection you already had before vaccination. Keep up with screening from 21 to 65 at the interval your doctor recommends, and see your doctor about bleeding after sex, between periods or after menopause.

Is it safe to buy erectile dysfunction pills online?

Products sold online or in stores as natural sexual enhancers are risky. The FDA has found many contain hidden prescription drugs, which can be dangerous, especially for people taking nitrate medicines for heart problems. New erectile problems can be an early sign of heart disease or diabetes, so see your doctor, who can check your health and prescribe a safe treatment if suitable.

Can a teen get sexual health care without a parent?

In most cases teens can get confidential STI testing and treatment without a parent's permission, and in many states they can also get contraception, but the rules vary by state. Title X family planning clinics and health department clinics are used to providing confidential care to young people. Ask the clinic about confidentiality, including how insurance statements are handled.

What should I do after a sexual assault?

Get to a safe place, and call 911 if you are in danger. A hospital emergency room can give medical care, emergency contraception, PEP to prevent HIV, and treatment to prevent other infections, and offer a forensic exam, whether or not you report to police. PEP must start within 72 hours. The National Sexual Assault Hotline, 1-800-656-4673, offers confidential support any time.

When to speak to a doctor

See your doctor or a sexual health clinic promptly for unusual discharge, pain when urinating, genital sores, lumps or warts, pain during sex, bleeding between periods, after sex or after menopause, or new erectile problems. Get urgent care for lower abdominal pain with fever, or testicular pain and swelling, which can affect fertility. Go to an emergency room or urgent care within 72 hours of a possible HIV exposure or a sexual assault to ask about PEP. Go to the ER for sudden severe testicular pain or an erection that will not go down. Call 911 for chest pain during or after sex, severe one-sided pelvic pain, shoulder-tip pain or fainting in early pregnancy, heavy bleeding with dizziness or fainting, or if you are in danger. If you feel unable to cope or have thoughts of harming yourself, call or text 988.

Where this comes from

• CDC — Sexually Transmitted Infections Treatment Guidelines, 2021
• US Preventive Services Task Force — Chlamydia and Gonorrhea: Screening
• CDC — Getting Tested for HIV
• US Preventive Services Task Force — Prevention of Human Immunodeficiency Virus (HIV) Infection: Preexposure Prophylaxis
• US Preventive Services Task Force — Cervical Cancer: Screening
• CDC — HPV Vaccination Recommendations
• CDC — U.S. Medical Eligibility Criteria for Contraceptive Use, 2024
• American College of Obstetricians and Gynecologists — Emergency Contraception
• American College of Obstetricians and Gynecologists — Evaluating Infertility
• HHS — Title X Family Planning Program

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.