Irregular periods

Differential Diagnosis

• Hypothyroid: typically cause amenorrhea; characterized by decreased LH/FSH/estradiol/progesterone
  • Structural
    • Mass lesion, such as craniopharyngioma
    • Infiltration
  • Functional from stress, exercise, or diet: typically associated with weight changes, triggered by weight los
• Pituitary: typically cause amenorrhea; characterized by decreased LH/FSH/estradiol/progesterone
  • Structural
    • Adenoma, such as prolactinoma
    • Sheehan syndrome
    • Infiltration
  • Functional
    • Prolactinoma
    • Cushing syndrome
• Ovaries: characterized by increased LH/FSH and decreased estradiol/progesterone
  • Ovarian failure
    • Primary/premature ovarian failure
    • Iatrogenic (surgery)
    • Genetic, such as Fragile X syndrome or Turner syndrome
  • Polycystic ovarian syndrome (PCOS): causes oligo-amenorrhea, with irregularly irregular periods
  • Malignancy, such as angrogen-producing tumours like Sertoli tumours
• Uterus
  • Malignancy
• Others
  • Thyroid disease: changes flow, not frequency (increased flow in hypothyroidism and decreased flow in hyperthyroidism)
  • Congenital adrenal hyperplasia (CAH)