Causes

Abnormal vaginal bleeding can relate to an issue with your reproductive system (a gynecologic condition) or to other medical problems or certain medications.

If you're in menopause — generally defined as 12 months, give or take, without a menstrual period — any vaginal bleeding may be a cause for concern and should be evaluated.

Possible causes of abnormal vaginal bleeding include:

Cancers and precancerous conditions

• Cervical cancer
• Endometrial cancer (uterine cancer)
• Endometrial hyperplasia
• Ovarian cancer
• Uterine sarcoma
• Vaginal cancer

Endocrine system factors

• Hyperthyroidism (overactive thyroid)
• Hypothyroidism (underactive thyroid)
• Polycystic ovary syndrome (PCOS)
• Stopping or changing birth control pills or menopausal hormone therapy (withdrawal bleeding)

Fertility and reproduction factors

• Ectopic pregnancy
• Fluctuating hormone levels
• Miscarriage (before the 20th week of pregnancy)
• Pregnancy
• Random ovulatory cycles
• Sexual intercourse
• Perimenopause
• Vaginal atrophy (genitourinary syndrome of menopause)

Infections

• Cervicitis
• Chlamydia trachomatis
• Endometritis
• Gonorrhea
• Pelvic inflammatory disease (PID)
• Ureaplasma vaginitis
• Vaginitis

Medical conditions

• Celiac disease
• Severe systemic disease, such as kidney or liver disease
• Thrombocytopenia (low platelet count)
• Von Willebrand disease (and other blood clotting disorders)

Medications and devices

• Forgotten (retained) tampon
• Intrauterine device (IUD)
• Stopping or changing birth control pills or menopausal hormone therapy (withdrawal bleeding)
• Tamoxifen side effect

Noncancerous growths and other uterine conditions

• Adenomyosis
• Cervical polyps
• Endometrial polyps
• Uterine fibroids
• Uterine polyps

Trauma

• Blunt trauma or penetrating injury to the vagina or cervix
• Sexual abuse