The most common symptom of uterine cancer after menopause is vaginal bleeding, and it appears in about 90% of women eventually diagnosed with the disease. Any bleeding after menopause, even light spotting, is considered abnormal and worth investigating. That said, only about 9% of women who experience postmenopausal bleeding turn out to have endometrial cancer, so while the symptom demands attention, it is far more often caused by something benign.
Postmenopausal Bleeding Is the Primary Warning Sign
Once you’ve gone 12 consecutive months without a period, any vaginal bleeding that returns is classified as postmenopausal bleeding. It can range from faint pink spotting on toilet paper to heavier, period-like flow. Both count. A large meta-analysis of over 40,000 patients found that 90% of women with endometrial cancer had reported bleeding before their diagnosis, making it by far the most reliable early signal.
The reassuring side of that statistic: roughly 91% of postmenopausal bleeding is caused by something other than cancer. Common culprits include thinning of the vaginal or uterine lining, noncancerous polyps, or hormonal shifts. Polyps, for instance, carry only about a 3% cancer risk. But there’s no way to tell the difference between benign and malignant bleeding based on how it looks or how much there is. Even a single episode of spotting years after your last period warrants evaluation.
If you’re on hormone replacement therapy, some irregular bleeding during the first six months is expected. Persistent bleeding beyond that window, however, raises more concern and should prompt testing.
Other Symptoms Beyond Bleeding
Bleeding gets the most attention because it shows up early and is hard to ignore, but uterine cancer can produce other symptoms, especially as it progresses.
Unusual vaginal discharge. Some women notice a watery, blood-tinged, or dark-colored discharge that may have an unpleasant odor. This can appear with or without active bleeding. Discharge that is bloody, dark, or foul-smelling is sometimes the first noticeable change, particularly in cancers that don’t produce heavy bleeding right away.
Pelvic pain or pressure. A persistent ache or sense of heaviness low in the abdomen or pelvis can develop as the tumor grows. This is different from the brief cramping some women feel occasionally. It tends to be more constant and may worsen over weeks or months. Cramping in the lower abdomen, just below the belly, is another reported symptom.
Pain during intercourse. Discomfort or pain with sexual activity can occur when the cancer involves the cervix or lower uterus.
Painful urination. When the tumor presses against or grows near the bladder, urination can become uncomfortable or more frequent.
Symptoms of More Advanced Disease
Early-stage uterine cancer is usually confined to the inner lining of the uterus, which is why bleeding tends to be the first and sometimes only symptom. As the disease progresses beyond the uterus, symptoms broaden. In stage IV, cancer has spread past the pelvis into organs like the intestines or liver, and symptoms at that point reflect whichever organs are involved: changes in bowel habits, abdominal bloating, unexplained weight loss, or fatigue.
The good news is that most uterine cancers are caught relatively early, precisely because postmenopausal bleeding is alarming enough that women seek care. Cancers detected while still limited to the uterus carry a significantly better prognosis than those found after spread.
What Raises Your Risk
Certain factors make uterine cancer more likely after menopause. Being over 50, having obesity, and taking estrogen-only hormone replacement therapy (without progesterone) are three of the most significant. Excess body fat produces estrogen, which stimulates the uterine lining and, over time, can drive abnormal cell growth. This is why uterine cancer rates have risen alongside obesity rates.
Women using estrogen-only hormone replacement have a higher risk than those using combined estrogen-progesterone therapy, because progesterone counteracts estrogen’s effect on the uterine lining. If you’ve been on estrogen-only therapy and experience bleeding, that context matters for your evaluation.
How Postmenopausal Bleeding Gets Evaluated
The standard first step is a transvaginal ultrasound to measure the thickness of the uterine lining. In postmenopausal women, a lining of 4 millimeters or less has a greater than 99% negative predictive value for cancer, meaning it’s extremely unlikely cancer is present. A thicker lining, or a lining that can’t be clearly measured on ultrasound, triggers further investigation.
That next step is typically a tissue sample from the uterine lining, which is examined under a microscope. This is the only definitive way to rule cancer in or out. Among women whose ultrasound shows a thickened lining, the cancer risk climbs to about 19%, so biopsy becomes especially important in that group.
One important caveat: rare types of uterine cancer can develop even when the lining appears thin on ultrasound. For this reason, repeated or ongoing postmenopausal bleeding should be evaluated with a tissue sample regardless of what the ultrasound shows. A single reassuring ultrasound doesn’t close the door if bleeding continues.
What Most Bleeding Turns Out to Be
Because 9 out of 10 cases of postmenopausal bleeding are not cancer, it helps to know the more common explanations. Vaginal atrophy, where the vaginal walls thin and dry out due to lower estrogen, is one of the most frequent causes. Endometrial atrophy (thinning of the uterine lining itself) and benign polyps are also common. These conditions can produce spotting, light bleeding, or discharge that looks very similar to what cancer might cause.
The overlap in symptoms is exactly why evaluation matters. There is no way to distinguish a benign cause from a malignant one based on symptoms alone. The volume of bleeding, the color, or the presence of pain doesn’t reliably separate one from the other. Testing does.