Postmenopausal Bleeding: Why Even One Spot Needs a Check
Postmenopausal bleeding is any vaginal bleeding after menopause, and the NHS says to get it checked even if it's a small amount or happened once. Most cases aren't cancer: thinning of the vaginal or womb lining and polyps are common causes. But in a large review, about 9% of women with it had endometrial cancer.
A single spot of blood a year or two after your last period is easy to explain away. It was only once, it was barely anything, maybe it was a scratch. I understand the instinct, and it's exactly the instinct the NHS asks you to override.
This guide covers what counts as postmenopausal bleeding, why it needs checking even when it's tiny, the common causes and the less common ones, what happens at the appointment, what the ultrasound measurement means, and how the rules change if you're taking HRT.
What counts as postmenopausal bleeding?
The NHS defines it as bleeding from the vagina after your menopause, and notes that menopause is usually diagnosed in women over 45 who haven't had a period for more than a year. It says to see a GP if you notice bleeding after your menopause, "even if it's only a small amount or it's only happened once."
If you're still in perimenopause, irregular bleeding is a different situation, and our guide to perimenopause spotting covers it. If you're on HRT, some bleeding can be an expected side effect for the first months; the section on HRT below explains where the line sits.
Don't wait to see if it happens again. The NHS files this under non-urgent advice and says to see a GP, but it's clear that it needs checking: "Postmenopausal bleeding is not usually serious, but it's important to get checked because it can be a sign of cancer. Cancer may be easier to treat if it's found early."
How likely is it to be cancer?
Most of the time, it isn't. A 2018 review of 129 studies found a pooled endometrial cancer risk of 9% among women with postmenopausal bleeding. Turned around, though, the same review found that 91% of women with endometrial cancer had experienced postmenopausal bleeding, which is why the symptom is taken seriously.
The American College of Obstetricians and Gynecologists (ACOG) puts the same point from the clinical side. It notes that cancer of the endometrium is the most common type of gynecologic cancer in the United States, and that vaginal bleeding is "the presenting sign in more than 90% of postmenopausal women with endometrial carcinoma." The review also found that the risk estimate varied with the use of hormone therapy, though its summary doesn't say which group had the higher figure.
What are the common causes?
The NHS lists three as the most common: thinning of the vaginal or womb lining, polyps, and a thickened womb lining. Cancer is on its list too, but as a less common cause. Each is described below, followed by the risk factors doctors weigh alongside them.
- Thinning and inflammation of the lining of the vagina (atrophic vaginitis) or womb (endometrial atrophy), caused by lower estrogen levels.
- Cervical or womb polyps, growths that are usually non-cancerous.
- A thickened womb lining (endometrial hyperplasia), which the NHS says can be caused by HRT, high levels of estrogen or being overweight, and can lead to womb cancer.
- Less commonly, cancer, such as womb cancer or ovarian cancer.
ACOG lists clinical risk factors for endometrial cancer that doctors should also consider, "including but not limited to" age, obesity, use of estrogen without a progestogen, certain medical conditions such as polycystic ovary syndrome and type 2 diabetes, and a family history of gynecologic cancer. In my reading, having one of these doesn't mean bleeding is cancer; it's part of the picture your doctor weighs.
What happens at the appointment?
Expect tests. In the UK, the NHS says a GP should refer you to hospital or a postmenopausal bleeding clinic and that you shouldn't have to wait more than 2 weeks to see a specialist. ACOG describes the US approach as requiring "prompt and efficient evaluation."
The NHS says the tests may include:
- a vaginal ultrasound scan, with a small device placed in the vagina;
- an examination of the pelvis and vagina, sometimes with a speculum so the cervix can be seen;
- a hysteroscopy, in which a thin camera is passed through the cervix into the womb to look for problems and take a tissue sample (biopsy), under local or general anesthetic;
- the specialist pressing on your tummy and inside the vagina to check for lumps, tenderness or swelling.
In the UK, NICE's suspected cancer guideline recommends a suspected cancer pathway referral for women aged 55 and over with unexplained postmenopausal bleeding that can't be attributed to HRT, and says to consider one for women under 55.
What does the ultrasound measurement mean?
The key number is the thickness of the womb lining, measured on a transvaginal ultrasound. ACOG says a thin lining of 4 mm or less makes endometrial cancer very unlikely, and that the scan is usually enough for an initial evaluation when the lining is that thin. Bleeding that keeps coming back is a different question, covered below.
ACOG calls ultrasound "a reasonable alternative to endometrial sampling as a first approach" for a first episode of bleeding. It adds that if blind sampling doesn't find hyperplasia or cancer, further testing, such as hysteroscopy with dilation and curettage, is warranted for women with persistent or recurrent bleeding.
One thing the scan is not: a screening test. ACOG says transvaginal ultrasound "is not an appropriate screening tool for endometrial cancer in postmenopausal women without bleeding," and that a lining over 4 mm found by chance in a woman without bleeding "need not routinely trigger evaluation," though an individual assessment based on risk factors is appropriate.
What if you're taking HRT?
Then some bleeding is expected: a regular withdrawal bleed on sequential HRT, and irregular bleeding early on. NICE says vaginal bleeding is a common side effect during the first 6 months of systemic HRT, or within 3 months of changing the dose or preparation, and that people should "seek medical help promptly" if unscheduled bleeding happens beyond those timeframes.
The NHS gives three reasons to speak to a GP while on HRT: irregular bleeding for more than 6 months after starting, bleeding that becomes heavier, or bleeding after you haven't had periods for a while. NICE also notes that evidence on unscheduled bleeding during HRT is limited, and points to guidance from the British Menopause Society. What's expected with each type of HRT is covered in our guide to HRT side effects.
How is it treated?
It depends entirely on the cause, which is why the tests come first. Atrophy may need no treatment at all, while womb or ovarian cancer often means surgery. The NHS summarizes the options for each cause, and the table below follows its list.
| Cause | Treatment the NHS describes |
|---|---|
| Vaginal or endometrial atrophy | May not need treatment, but may be offered estrogen cream or pessaries |
| Cervical polyps | May need to be removed by a specialist |
| Endometrial hyperplasia | Depending on the type, no treatment, hormone medicine (tablets or an intrauterine system) or a total hysterectomy |
| Side effect of HRT | Changing or stopping HRT |
| Womb cancer | Often a total hysterectomy, often followed by radiotherapy, chemotherapy, hormone therapy or a combination |
| Ovarian cancer | Surgery to remove the ovaries and sometimes the womb; chemotherapy may also be needed |
If the cause turns out to be atrophy, the estrogen cream or pessaries mentioned there are forms of vaginal estrogen, and our vaginal estrogen guide explains how they work and what the safety studies found.
Where to go from here
If you're still having periods, even irregular ones, our guide to irregular periods in perimenopause and our guide to heavy periods are the better fit. If you're on HRT and unsure whether your bleeding is expected, start with our HRT side effects guide. And if dryness or discomfort is part of the picture, our vaginal dryness guide covers the treatment options in order.
For how all of this connects to rest and recovery at night, start at the complete perimenopause and menopause sleep guide.
Key takeaways
- Any amount counts: the NHS says to get bleeding after menopause checked even if it's small or happened only once.
- Usually not cancer: atrophy, polyps and endometrial hyperplasia are the most common causes, according to the NHS.
- But sometimes it is: a review of 129 studies found a 9% pooled risk of endometrial cancer, and 91% of women with endometrial cancer had postmenopausal bleeding.
- Expect tests, which may include a vaginal ultrasound, an exam and a hysteroscopy with a biopsy; in the UK, a specialist within 2 weeks.
- A lining of 4 mm or less has a greater than 99% negative predictive value for endometrial cancer, per ACOG; and if blind sampling is negative, persistent or recurrent bleeding warrants further testing.
- On HRT, timing matters: bleeding is common in the first 6 months or within 3 months of a change; beyond that, NICE says unscheduled bleeding needs prompt medical help.
Frequently asked questions
Is a small amount of bleeding after menopause normal?
It should still be checked. The NHS says to see a GP if you notice bleeding from your vagina after your menopause, even if it is only a small amount or it has only happened once. It adds that postmenopausal bleeding is not usually serious, but it can be a sign of cancer.
What is the most common cause of postmenopausal bleeding?
The NHS lists the most common causes as thinning and inflammation of the vaginal or womb lining due to lower estrogen, cervical or womb polyps, and a thickened womb lining called endometrial hyperplasia. It says cancer, such as womb or ovarian cancer, is a less common cause.
How likely is postmenopausal bleeding to be cancer?
In a 2018 review of 129 studies, the pooled risk of endometrial cancer among women with postmenopausal bleeding was 9%. Estimates ranged from 5% in North America to 13% in Western Europe, though that regional difference was not statistically significant. The same review found that 91% of women with endometrial cancer had postmenopausal bleeding.
What tests are done for postmenopausal bleeding?
The NHS says tests may include a vaginal ultrasound scan, an examination of the pelvis and vagina, and a hysteroscopy, in which a thin camera looks inside the womb and a tissue sample can be taken. The American College of Obstetricians and Gynecologists says a transvaginal ultrasound is usually enough for an initial evaluation if the lining is 4 mm or thinner.
Is bleeding on HRT the same as postmenopausal bleeding?
Not always. NICE says vaginal bleeding is a common side effect in the first 6 months of systemic HRT, or within 3 months of changing the dose or preparation, and that unscheduled bleeding beyond those timeframes needs prompt medical help. The NHS also says to see a GP if bleeding on HRT becomes heavier.
What does an endometrial thickness of 4 mm or less mean?
In a woman with postmenopausal bleeding, the American College of Obstetricians and Gynecologists says an endometrial thickness of 4 mm or less on transvaginal ultrasound has a greater than 99% negative predictive value for endometrial cancer. It adds that if blind sampling does not find hyperplasia or cancer, persistent or recurrent bleeding warrants further testing, such as hysteroscopy.
Sources cited
- NHS. Postmenopausal bleeding. Page last reviewed September 24, 2026. www.nhs.uk/symptoms/post-menopausal-bleeding
- Clarke MA, Long BJ, Del Mar Morillo A, et al. Association of endometrial cancer risk with postmenopausal bleeding in women: a systematic review and meta-analysis. JAMA Intern Med. 2018;178(9):1210-1222. pubmed.ncbi.nlm.nih.gov/30083701
- ACOG Committee Opinion No. 734: The role of transvaginal ultrasonography in evaluating the endometrium of women with postmenopausal bleeding. Obstet Gynecol. 2018;131(5):e124-e129. doi.org/10.1097/AOG.0000000000002631
- National Institute for Health and Care Excellence. Suspected cancer: recognition and referral (NG12). Endometrial cancer recommendations. www.nice.org.uk/guidance/ng12/chapter/Recommendations-organised-by-site-of-cancer
- National Institute for Health and Care Excellence. Menopause: identification and management (NG23). Recommendations 1.8.4 and 1.8.5. www.nice.org.uk/guidance/ng23/chapter/Recommendations
- NHS. Side effects of hormone replacement therapy (HRT). www.nhs.uk/medicines/hormone-replacement-therapy-hrt/side-effects-of-hormone-replacement-therapy-hrt
How this article was checked
The NHS pages and NICE guidelines NG12 and NG23 were read in full. The 2018 review and the ACOG Committee Opinion come from their published abstracts, and every quote from them appears as written. The NHS describes the UK referral route (a specialist within 2 weeks); US practice may differ.
An independent fact-check found no serious errors; it led to small corrections in an earlier draft, mostly to keep timing and levels of urgency exactly as the sources state them.
It has not been reviewed by a clinician. Ellen Hayes is a researcher and writer, not a doctor, and nothing here is a diagnosis or a substitute for being seen by one.
Ellen Hayes
Health & Wellness Writer and Researcher
Hi — I'm Ellen. This is the one symptom in midlife where I'd never tell you to wait and see. Most of the time the answer is reassuring, but you only get that answer by asking.
I'm not a doctor. I'm not an expert — and I'm never going to talk down to you like one. I'm a woman in the middle of perimenopause who got tired of vague answers, started reading the actual research, and writes it down here in plain English, the way I'd explain it to a friend over coffee. More about Ellen →