Mpox is a viral illness caused by the monkeypox virus, a relative of smallpox. It spreads mainly through close skin-to-skin contact, including sex, and causes a painful or itchy rash that often appears on the genitals, anus, or mouth, sometimes with fever and swollen lymph nodes. Most people recover fully within a few weeks.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | exam + lab |
| If you may have it | get tested — testing, not symptoms, decides |
What is mpox?
Mpox is an infection caused by the monkeypox virus, which belongs to the same family as the virus that causes smallpox CDC, About Mpox. The clade II strain drove the global outbreak that began in 2022. That wave spread primarily through close skin-to-skin contact, including intimate and sexual contact, and affected mostly men who have sex with men. This is an epidemiological observation. A virus that passes through skin contact moves fastest through whatever sexual network it lands in first, and dense partner networks let it circulate before anyone connects the dots.
The illness itself is usually self-limiting, and most people recover with nothing more than time and pain control. But mpox is not uniformly mild. In people who are immunocompromised, especially those with advanced HIV, it can become severe and even life-threatening, so early recognition matters.
What are the symptoms of mpox?
The hallmark is a rash that can look like pimples or blisters, often painful or itchy CDC, signs & symptoms. The lesions can show up on the hands, feet, face, or mouth, but in the outbreak among sexually active adults they frequently appear right where contact happened: the genitals, the anus, or inside the mouth. A single sore on the penis or around the anus that you'd otherwise dismiss as an ingrown hair or a herpes outbreak can be mpox, which is part of why it gets missed.
Alongside the rash, many people get fever, swollen lymph nodes, muscle aches, deep exhaustion, and respiratory symptoms like a sore throat. Swollen lymph nodes are a useful clue, since they're more typical of mpox than of look-alike rashes.
The silent reality: not everyone gets a warning
Older descriptions of mpox emphasize a prodrome of fever and aches that arrive before the rash. In the recent outbreak, that script broke. Some people get the rash with no warning illness at all, and others have so few lesions that they never suspect anything serious. A person can have a couple of small anal or genital sores, feel basically fine, and still be infectious, so they keep having contact because they don't feel sick.
How does mpox spread?
Mpox spreads mainly through close contact, including intimate and sexual contact, with someone who has it CDC, prevention. It can also pass through contact with contaminated materials like bedding or towels, through contact with infected animals, and from a pregnant person to the fetus. All of these involve direct contact with the rash or the fluid in the lesions.
This is why condoms alone are probably not enough. A condom covers the penis, but mpox lesions can sit on the scrotum, the perineum, the thighs, the hands, or the mouth, and infectious respiratory secretions may be present during close face-to-face contact. Condoms still help, but they're one layer.
When symptoms start after exposure
The incubation period runs 3 to 17 days, and people usually get sick within 21 days of contact CDC, clinical overview. Once symptoms begin, the illness typically lasts two to four weeks. If you had a recent exposure and you're counting the days, our breakdown of how long after mpox exposure do symptoms start? walks through what to watch for at each stage.
How is mpox tested and diagnosed?
Mpox is confirmed by detecting the virus's DNA with a PCR test run on a swab of a suspected lesion. A clinician rubs the swab firmly across one or more sores to collect the sample. There's no blood draw or urine cup for this one, because the virus is in the rash itself. If you have no lesions yet, there's nothing to swab, so testing waits until the rash appears.
In practice this is a quick clinic visit: a brief exam, a swab of a sore, and results usually back in a few days. Many health departments, Planned Parenthood sites, and Title X clinics offer it at low or no cost. If you're sorting out where to go and what's covered, here's how to get tested, and you can compare testing providers before you book. For more on the swab itself and what to expect, see our guide to mpox testing.
One caveat on timing: mpox testing relies on a visible lesion, so it doesn't follow the same window logic as a blood-based STI. For everything else you may have been exposed to, our guide on when to test after exposure covers the right timing for each infection.
How is mpox treated?
Most people without severe disease recover with supportive care: managing pain, keeping lesions clean, and waiting out the illness CDC, clinical care. Genital and anal sores can be painful, so pain control and stool softeners (for anal lesions) are a real part of feeling functional during the worst week or two.
The antiviral tecovirimat, brand name TPOXX, is considered for people with severe disease or those at high risk of it, such as people with advanced HIV, and it's accessed through CDC channels CDC, tecovirimat. Clinical trials found tecovirimat safe, but it did not speed lesion healing, so it isn't handed to everyone with a few sores. It's reserved for the people most likely to get seriously ill.
As with any infection you treat, the practical rule holds. If you're given a defined course, finish all of it even once you feel better, and ask your clinician whether recent partners should be evaluated so the virus doesn't keep circulating.
What happens if mpox is left untreated or becomes severe?
For most healthy people, mpox runs its course without lasting harm. The danger concentrates in people who are immunocompromised, particularly those with advanced, untreated HIV. In that group, mpox can cause serious complications:
- Eye infection, where lesions on or around the eye can threaten vision if not treated.
- Neurologic complications, including inflammation affecting the brain or nerves.
- Heart inflammation (myocarditis), swelling of the heart muscle that can impair how the heart pumps.
- Widespread, slow-healing lesions and secondary bacterial infection of the skin.
In these settings mpox can be life-threatening, which is why advanced HIV triggers antiviral treatment and close monitoring rather than watch-and-wait.
How can you prevent mpox?
The single most effective tool is vaccination. The two-dose JYNNEOS vaccine is recommended for people at increased risk, with the second dose given 28 days after the first CDC, JYNNEOS. One shot gives partial protection, and the series is built to be completed. If you're trying to figure out whether you qualify and where to get it, start with our guide to the mpox vaccine.
Beyond vaccination, practical prevention comes down to contact:
- Avoid skin-to-skin contact with anyone who has a new or unexplained rash, and skip sex until a partner's rash is checked out.
- Use condoms every time. They lower risk for sexually transmitted infections and reduce mpox risk, even though they don't eliminate it.
- Don't share bedding, towels, or sex toys with someone who has active lesions.
- Keep up routine STI testing, since it catches the infections that cause no symptoms, and ask about JYNNEOS if you're in a higher-risk group.
When should you see a clinician?
See a clinician if you develop a new rash, sores, or blisters, especially on the genitals, anus, or mouth, whether or not you feel sick otherwise, and particularly after close or sexual contact with a new partner. Get seen promptly if you live with HIV or another condition that weakens your immune system, because you're the group most likely to benefit from early antiviral treatment. And if you've had a known exposure, ask about post-exposure vaccination, which can blunt the illness if given soon enough. A new genital sore is common, treatable, and something clinics handle every day; it says nothing about who you are.