Oligomenorrhea

Abnormally infrequent menstrual bleeding, characterized by menstrual cycles longer than 35 days, reduced menstrual frequency, and often decreased volume of endometrial shedding.

Causes

• Endocrine and hormonal causes

  • Polycystic ovary syndrome

  • Hypothyroidism

  • Hyperthyroidism

  • Hyperprolactinemia

  • Diabetes mellitus

  • Cushing syndrome

  • Hypothalamic–pituitary disorders affecting gonadotropin secretion

• Hormonal contraceptives

  • Oral contraceptive pills

  • Hormonal intrauterine devices

  • Injectable contraceptives

• Perimenopause-related hormonal changes

• Ovarian insufficiency

• Lifestyle and physiological causes

  • Extreme endurance training

  • Excessive physical exercise

  • Low body weight

  • Eating disorders (anorexia nervosa)

  • Caloric restriction

  • Psychological stress

  • Sleep disturbances

• Pelvic inflammatory disease

• Pregnancy-related hormonal changes

• Postpartum or lactational amenorrhea/oligomenorrhea

• Medications affecting hormonal regulation