Menopause is officially defined as the point in time when a person has gone twelve consecutive months without a menstrual period, confirming the end of the reproductive years and a decline in hormone production. Postmenopausal Bleeding (PMB) is any instance of vaginal bleeding, spotting, or staining that occurs after this full year of amenorrhea. This bleeding is distinct from the irregular flow that occurs during perimenopause, the transition period leading up to menopause. Even a single episode of light spotting falls under the definition of PMB and warrants attention.
Why Bleeding After Menopause Requires Immediate Evaluation
The answer to whether postmenopausal bleeding stops on its own is unequivocally no; any occurrence must be investigated by a healthcare provider. Bleeding after menopause is never considered normal. While many underlying causes of PMB are benign, it acts as an early warning sign for conditions requiring prompt diagnosis.
This symptom is the primary indicator of endometrial cancer, a malignancy of the uterine lining and the most common gynecological cancer. Approximately 90% of people diagnosed with endometrial cancer first sought medical attention due to PMB. Although only about 10% of women presenting with postmenopausal bleeding receive a cancer diagnosis, the symptom cannot be ignored until a malignant cause is ruled out.
Immediate evaluation is necessary because early diagnosis significantly improves treatment outcomes. Endometrial cancer is typically detected at an early stage because PMB prompts patients to seek care before the disease progresses. The prognosis is more favorable when the cancer is confined to the uterus. Delaying an evaluation allows any potential serious condition to progress, missing the window for effective treatment.
Common Non-Malignant Sources of Bleeding
The most frequent causes of postmenopausal bleeding relate to the natural decline in estrogen levels and are not cancerous. The most common source is genitourinary syndrome of menopause (GSM), which includes both vaginal atrophy and endometrial atrophy. Vaginal atrophy occurs when the vaginal lining becomes thin, dry, and fragile due to lack of estrogen, making it prone to bleeding from minor trauma, such as sexual intercourse.
Endometrial atrophy, the most common single cause of PMB, involves the thinning of the uterine lining. This tissue can become delicate and unstable, leading to spontaneous spotting or light bleeding.
Benign growths, such as endometrial or cervical polyps, are also frequent non-malignant culprits. These polyps are overgrowths of tissue that attach to the uterine or cervical wall and bleed easily when irritated. Polyps are often removed because they can sometimes conceal a precancerous area, and their removal resolves the bleeding.
Unscheduled bleeding can also be a side effect of systemic medications, most notably Hormone Replacement Therapy (HRT). Women taking sequential or cyclical HRT are expected to have a period-like withdrawal bleed after the progesterone phase. However, unscheduled bleeding outside of this expected time, or persistent bleeding beyond the first six months of continuous combined HRT, must be investigated.
Serious Conditions Requiring Prompt Treatment
While less common than atrophic causes, certain conditions causing PMB require prompt intervention due to their potential to become malignant. Endometrial hyperplasia is a pre-cancerous condition where the lining of the uterus thickens excessively. This thickening often results from unopposed estrogen stimulation, such as from certain types of HRT or high body weight.
Endometrial hyperplasia is categorized based on the presence of abnormal cells, or atypia, and is considered a direct precursor to endometrial cancer. Simple hyperplasia without atypia carries a low risk of progression. However, complex hyperplasia with atypia has a significantly higher risk of developing into carcinoma. Treatment focuses on reversing the thickening with progestin therapy or, in cases of complex atypical hyperplasia, surgical removal of the uterus.
The most concerning cause is endometrial cancer itself, which is typically slow-growing and highly curable when detected early. Most endometrial cancers are diagnosed at Stage I, confined to the uterus. Less commonly, PMB can be a symptom of other gynecologic malignancies, such as cervical or ovarian cancer.
Cervical cancer may cause bleeding after menopause, often after sexual activity. Ovarian cancer presenting with PMB is rare. The immediate investigation of PMB ensures that both pre-cancerous hyperplasia and early-stage cancer are identified while treatments are maximally effective.
How Postmenopausal Bleeding is Diagnosed
The investigation of postmenopausal bleeding follows a standardized sequence to quickly determine the source of the bleeding and rule out malignancy. The initial diagnostic step is often a Transvaginal Ultrasound (TVUS) to visualize and measure the endometrial thickness (ET). This procedure uses sound waves via a small probe inserted into the vagina to image the uterine lining.
If the endometrial thickness measures four millimeters or less, the likelihood of endometrial cancer is extremely low, and further invasive testing may not be necessary. However, if the thickness is greater than four millimeters, or if the bleeding persists despite a thin lining, tissue sampling is mandated. The definitive test for ruling out cancer or hyperplasia is an Endometrial Biopsy (EMB).
An EMB is an office procedure where a thin, flexible tube is inserted through the cervix to collect a small sample of the uterine lining. This tissue is sent to a laboratory for histological evaluation to check for abnormal cells. If the biopsy is non-diagnostic, or if the clinician suspects a focal lesion like a polyp, a Hysteroscopy may be performed. Hysteroscopy involves inserting a tiny camera into the uterus to directly visualize the lining and guide targeted biopsies or polyp removal.