Differential Diagnosis for Absence of Menstrual Cycle for One Month

• Single Most Likely Diagnosis
  • Pregnancy: This is the most common cause of secondary amenorrhea (absence of menstrual cycle) and should always be considered first, especially in women of childbearing age.
• Other Likely Diagnoses
  • Stress or Weight Changes: Significant stress or changes in weight can disrupt the normal menstrual cycle by affecting the hypothalamic-pituitary-adrenal axis.
  • Hormonal Imbalance: Conditions like polycystic ovary syndrome (PCOS), thyroid disorders, or hyperprolactinemia can lead to irregular or absent menstrual cycles.
  • Contraceptive Use: Certain contraceptives, especially those that are hormonal, can cause changes in menstrual patterns, including absence of menstruation.
• Do Not Miss Diagnoses
  • Pituitary Tumor: Although rare, a tumor in the pituitary gland can disrupt hormone production, leading to amenorrhea. Missing this diagnosis could lead to serious health consequences.
  • Premature Ovarian Failure: Early menopause can cause the cessation of menstrual cycles. This condition can have significant psychological and health implications if not addressed.
  • Asherman Syndrome: This condition, characterized by scarring in the uterus, can cause amenorrhea. It often results from uterine surgery, such as a dilation and curettage (D&C).
• Rare Diagnoses
  • Genetic Disorders: Certain genetic conditions, such as Turner syndrome or Swyer syndrome, can affect the development of the reproductive system and lead to amenorrhea.
  • Autoimmune Disorders: Some autoimmune diseases can affect the endocrine system and lead to hormonal imbalances that disrupt menstrual cycles.
  • Tumor of the Reproductive Organs: Rarely, tumors of the ovaries, uterus, or other reproductive organs can cause amenorrhea by disrupting normal hormonal function.