Mycoplasma genitalium often causes no symptoms in women, but when it does, the most common signs are cervicitis-related: unusual vaginal discharge, bleeding between periods or after sex, pain during intercourse, and a burning feeling when urinating. Many women have a silent infection and only learn of it when a partner has symptoms or after fertility or pelvic problems arise.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | NAAT / lab |
| Often | no symptoms |
| If you may have it | get tested — testing, not symptoms, decides |
What is Mgen, and why does it behave this way in women?
Mgen is shorthand for mycoplasma genitalium, a sexually transmitted bacterium that lacks a cell wall, so penicillins and cephalosporins, the antibiotics that attack cell walls, don't work against it CDC, 2021. In women the organism settles on the cervix and can trigger cervicitis (inflammation of the cervix). It's an established cause of cervicitis and a quietly growing one. Many infections produce no symptoms, more so in women than in men.
The common symptoms in women
When Mgen does cause symptoms, they come from inflammation of the cervix and the urinary tract. None of them are unique to Mgen. They overlap with chlamydia, gonorrhea, and other causes of cervicitis, which is part of the problem.
- Abnormal vaginal discharge — a change in color, amount, or smell from the inflamed cervix is one of the most common complaints.
- Burning or stinging with urination (dysuria), which happens when the urethra is inflamed alongside the cervix and is easy to mistake for a simple urinary tract infection.
- Pelvic or lower-abdominal discomfort, usually a dull ache rather than a sharp pain in uncomplicated infection.
- Irritation or soreness around the vaginal opening that doesn't clearly point to one cause.
Female-specific symptoms: cervicitis and bleeding
Cervicitis is the hallmark of Mgen in women, and its giveaway signs involve bleeding from an inflamed, fragile cervix. The two patterns to know are post-coital bleeding (spotting or light bleeding after sex, because friction irritates the swollen cervical surface) and intermenstrual bleeding (spotting between periods, unrelated to your normal cycle). Pain during intercourse (dyspareunia) is also common when the cervix is inflamed. Take these symptoms seriously, because they're easy to brush off as a hormonal blip or rough sex.
Many women never notice any of this. Asymptomatic infection is frequent, so Mgen can persist and be passed on without a single warning sign, doing quiet damage along the way.
Throat and rectal infection
Mgen primarily infects the genital tract. Throat and rectal infection are far less central to the picture than they are for gonorrhea or chlamydia, and the established disease burden in women centers on the cervix and urethra. If you've had receptive anal sex and have rectal symptoms, mention it to your clinician so the right site can be evaluated, but routine throat and rectal testing isn't a standard part of Mgen care.
How soon do symptoms appear?
There's no neat, fixed incubation window for Mgen, and because so many infections are silent, the start of symptoms can be hard to pin to a specific encounter. Testing too soon after exposure can miss an early infection, so check our guide on when to test after exposure before you book. When symptoms appear, they tend to build gradually rather than hit overnight.
What Mgen is mistaken for
Because Mgen's symptoms are non-specific, it gets confused with several other conditions, and that confusion delays the right treatment.
- Chlamydia or gonorrhea — the discharge, dysuria, and cervicitis look nearly identical, and a standard STI panel won't detect Mgen unless a specific test is ordered.
- A urinary tract infection — the burning with urination sends many women to a UTI antibiotic that does nothing for Mgen.
- A yeast or bacterial vaginosis flare — abnormal discharge gets self-treated over the counter while the real cause persists.
- "Normal" spotting — post-coital or mid-cycle bleeding gets blamed on hormones or birth control.
A common, costly mistake is taking a leftover or single-dose antibiotic and assuming the problem is solved. With Mgen, the wrong drug doesn't just fail; it can push the bacteria toward resistance.
Complications and when it's an emergency
Untreated cervicitis can ascend into the upper reproductive tract, where Mgen turns serious. The complications below are why it's worth identifying and treating, even when symptoms are mild or absent.
- Pelvic inflammatory disease (PID) — infection spreading to the uterus, fallopian tubes, and ovaries, which can scar the tubes and is a recognized consequence of cervical Mgen.
- Infertility — Mgen is associated with about a twofold increased risk, largely through tubal damage from PID.
- Preterm delivery — Mgen during pregnancy is linked to delivering early.
- Persistent or recurrent cervicitis that doesn't clear because the strain is resistant to the antibiotic first tried.
Seek prompt care for warning signs of PID: severe lower-abdominal or pelvic pain, fever, pain during sex with bleeding, or feeling generally unwell. PID is treated more successfully the sooner it's caught, so don't wait it out.
Who should get tested?
There's no recommended routine screening of people without symptoms for Mgen NYSDOH/Johns Hopkins. Testing is targeted. You're a candidate if you have:
- Cervicitis or symptoms of it — abnormal discharge, post-coital or intermenstrual bleeding, or pelvic pain that hasn't been explained.
- Persistent or recurrent symptoms after being treated for chlamydia or gonorrhea, which can mean Mgen was the real culprit.
- Signs of PID, where Mgen should be considered as a cause.
- A partner diagnosed with Mgen.
If your partner is the one who's been diagnosed, read up on mgen partner treatment so you're both managed at the same time and don't re-infect each other.
How Mgen is confirmed
Mgen is diagnosed with a specific molecular (NAAT) test, not a standard STI panel, usually from a urine sample or a self-collected vaginal swab, with results back in a few days; testing is free or low-cost at health departments, Planned Parenthood, and Title X clinics. Clinics see it daily and it's treatable. When the lab can, it also checks for macrolide-resistance mutations to guide treatment. You can get tested and ask specifically for an M. genitalium test.
When to see a clinician
Book a visit if you have abnormal discharge, bleeding after sex or between periods, pain with sex, or burning with urination that isn't clearly a UTI — and especially if symptoms persisted after treatment for another infection. Mgen needs resistance-guided therapy: doxycycline first to lower the bacterial load, then azithromycin if the strain is macrolide-susceptible or moxifloxacin if it's resistant. Self-treating with random antibiotics backfires. For how cure works and why resistance complicates it, see is mycoplasma genitalium curable? treatment & resistance.