**Abnormal Vaginal Bleeding Explained**
Normal menstrual bleeding occurs every 21 to 35 days and follows a pattern with phases before and after ovulation. Abnormal vaginal bleeding is a common concern, affecting 10% to 30% of women of reproductive age, with substantial associated costs. The American College of Obstetricians and Gynecologists (ACOG) has introduced a classification system for this condition known as PALM COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy and Hyperplasia, Coagulopathy, Ovulatory Dysfunction, Endometrial, Iatrogenic, Not yet classified).
**Adolescents:**
- Common abnormal bleeding presentations in adolescents include anovulation, menorrhagia (heavy bleeding), and amenorrhea.
- Anovulation can occur for up to 18 months post-menarche due to the maturing hypothalamic-pituitary axis.
- Menorrhagia in adolescents can sometimes indicate a bleeding disorder, with up to 24% affected.
- Evaluation includes blood tests, coagulation profile, and von Willebrand disease screening if necessary. Treatment often involves hormonal contraception.
**Reproductive-Age Women:**
- Causes of abnormal bleeding in reproductive-age women include pregnancy complications, anovulatory disorders, and pelvic issues.
- Ovulatory cycles are characterized by regularity, premenstrual syndrome symptoms, and cervical mucus changes.
- Anovulatory cycles are unpredictable, resulting in various bleeding patterns.
- Evaluation depends on bleeding type and may involve blood tests, imaging, and endometrial biopsy.
- Anovulation, often related to PCOS or hypothalamic issues, can lead to irregular and unpredictable bleeding.
- Treatment is necessary to reduce endometrial cancer risk, typically with progesterone-induced withdrawal bleeding.
**Acute Bleeding Episodes:**
- In acute bleeding episodes, women are likely anovulatory. Evaluation includes hemoglobin assessment, volume status, and biopsy in older women.
- Severe cases may require hospitalization and intervention.
**Amenorrhea:**
- Secondary amenorrhea (absence of menses for at least 6 months) causes may include pregnancy, hormonal imbalances, and medications.
- Evaluation involves history, physical exam, pregnancy test, and hormone level tests.
- Progesterone-induced withdrawal bleeding helps diagnose underlying causes.
**Perimenopausal Women:**
- Abnormal bleeding is common in the years leading to menopause.
- Most often due to anovulation caused by declining ovarian function.
- Structural issues (fibroids or polyps) or bleeding disorders can also contribute.
- Evaluation includes endometrial biopsy, especially in high-risk women.
**Postmenopausal Women:**
- Postmenopausal bleeding (after 12 months without menstruation) raises concerns of endometrial carcinoma.
- Around 10-20% of such bleeding is due to malignancy.
- Evaluation may involve pelvic ultrasound and endometrial biopsy to assess endometrial thickness.
- A thin endometrial stripe (less than 4 mm) usually excludes cancer.
In cases of cervical stenosis, surgical procedures may be necessary when ultrasound results are inconclusive.