The most common reason for bleeding after menopause is endometrial or vaginal atrophy, accounting for roughly 38% of cases. This happens when declining estrogen levels cause the tissues lining the uterus or vagina to become thin, dry, and fragile enough to bleed. While atrophy is the leading cause and is not dangerous, about 9% of women with postmenopausal bleeding turn out to have endometrial cancer, so any bleeding after menopause warrants evaluation.
Atrophy: Why Thinning Tissue Bleeds
After menopause, your body produces far less estrogen than it did during your reproductive years. Estrogen is what kept the uterine lining and vaginal walls thick, moist, and resilient. Without it, those tissues gradually thin out and lose elasticity. The uterine lining can become so fragile that it sheds small amounts of blood spontaneously, and the vaginal walls can crack or bleed from minor friction, including during sex.
This condition, sometimes called genitourinary syndrome of menopause, can also cause vaginal dryness, irritation, and discomfort during intercourse. It tends to get progressively worse over time if untreated, since estrogen levels don’t recover on their own after menopause.
Other Common Causes
Endometrial polyps are the second most frequent cause, showing up in about 23% of postmenopausal bleeding cases. These are small, usually noncancerous growths that develop on the uterine lining. They can cause spotting or irregular bleeding, though some women with polyps have no symptoms at all. Polyps are typically removed through a minor procedure, both to stop the bleeding and to confirm they aren’t precancerous.
Endometrial hyperplasia, an overgrowth of the uterine lining, is less common but more concerning. When hyperplasia involves abnormal cell changes (called atypical hyperplasia), it carries a real risk of progressing to cancer. About 8% of women with simple atypical hyperplasia develop endometrial cancer if untreated, and that number climbs to nearly 30% for the complex atypical form.
Hormone therapy can also trigger bleeding. If you take a cyclic regimen that combines estrogen with progestin for 10 to 14 days each month, monthly bleeding is expected. Even continuous hormone therapy can cause spotting, though this often resolves within six months. Bleeding that starts after you’ve been on a stable hormone regimen for a while, or that becomes heavier than expected, should be evaluated separately.
Sometimes what seems like vaginal bleeding actually comes from nearby structures. Bleeding from the urethra or rectum can be mistaken for vaginal bleeding, especially when you notice blood on underwear or toilet paper without a clear source.
The Cancer Risk in Context
About 9% of women who experience postmenopausal bleeding are ultimately diagnosed with endometrial cancer. That number rises to about 12% among women not taking hormone therapy. Looked at from the other direction, roughly 90% of women who have endometrial cancer experienced postmenopausal bleeding as a symptom. This is why doctors take any amount of bleeding seriously, even a single episode of light spotting. The odds are strongly in your favor that the cause is benign, but the stakes of missing a cancer diagnosis are high enough that testing is standard.
How Postmenopausal Bleeding Is Evaluated
The first step is typically a transvaginal ultrasound to measure the thickness of the uterine lining. Both the American College of Obstetricians and Gynecologists and the British Gynaecological Cancer Society use 4 millimeters as the key threshold. A lining that measures 4 mm or thinner has a greater than 99% negative predictive value for endometrial cancer, meaning cancer is extremely unlikely. If the lining is thicker than 4 mm, further testing is needed.
That next step is usually an endometrial biopsy, where a thin instrument is passed through the cervix to collect a tissue sample. This is done in a doctor’s office and takes a few minutes, though it can cause cramping. Biopsy is good at detecting cancer in the uterine lining, but it has significant limitations for other conditions. Its sensitivity for detecting polyps is only about 8 to 29%, because the instrument samples blindly and can easily miss a small growth. When a polyp or other structural abnormality is suspected, hysteroscopy (where a tiny camera is inserted into the uterus) provides a much more accurate picture and allows removal of polyps at the same time.
Treatment for Atrophy-Related Bleeding
Since atrophy is the most common cause, many women end up with a treatment plan focused on restoring moisture and thickness to vaginal and uterine tissues. The simplest starting point is over-the-counter vaginal moisturizers, used every few days, or water- or silicone-based lubricants before intercourse. These don’t address the underlying tissue changes, but they reduce friction and discomfort.
When moisturizers aren’t enough, low-dose vaginal estrogen is the most effective option. It comes in several forms: a cream applied with an applicator, a small tablet or suppository inserted into the vagina, or a flexible ring that sits in the upper vagina and releases estrogen steadily for about three months. All of these deliver estrogen directly to the tissues that need it, with minimal absorption into the rest of the body. The typical pattern is daily use for the first one to three weeks, then tapering to a few times per week.
For women who prefer not to use estrogen, there are alternatives. One prescription option is a daily pill that helps relieve painful intercourse from moderate to severe tissue changes. Another is a nightly vaginal insert that delivers a hormone precursor called DHEA directly to the vaginal tissue. Vaginal dilators, which gently stretch and stimulate the tissues, can also help reverse narrowing and are sometimes used alongside estrogen therapy.
If vaginal dryness is part of a bigger picture that includes hot flashes and other systemic menopause symptoms, systemic hormone therapy through pills, patches, or gel may address multiple symptoms at once. This is a different conversation with a higher risk-benefit profile than localized vaginal estrogen.
What Bleeding Patterns Mean
The amount of bleeding doesn’t reliably indicate the cause. Atrophy can produce anything from faint spotting to noticeable bleeding. Polyps often cause intermittent spotting that comes and goes. Endometrial cancer can start with very light spotting that a woman might dismiss as insignificant. There is no “safe” pattern of postmenopausal bleeding that you can evaluate at home. A single episode of spotting, a pink or brown discharge, or recurrent light bleeding all justify the same workup. The evaluation is straightforward, and most women leave with a reassuring answer and a simple treatment plan.