Differential Diagnosis for Irregular Menstrual Periods but Absent Prior

• Single most likely diagnosis:
  • Polycystic Ovary Syndrome (PCOS): This is a common endocrine disorder in women of reproductive age, often presenting with irregular menstrual periods due to ovulation problems. The absence of prior regular periods could be a manifestation of PCOS, especially if accompanied by other symptoms like hirsutism, acne, or obesity.
• Other Likely diagnoses:
  • Thyroid Dysfunction: Both hypothyroidism and hyperthyroidism can cause menstrual irregularities. Thyroid hormones play a crucial role in regulating menstrual cycles, and any imbalance can lead to irregular periods.
  • Hyperprolactinemia: Elevated levels of prolactin can disrupt the normal menstrual cycle, leading to irregular periods. This condition can be caused by various factors, including pituitary tumors, certain medications, or thyroid disease.
  • Premature Ovarian Failure (POF): Also known as premature ovarian insufficiency, this condition occurs when the ovaries stop functioning and menstruation ceases before the age of 40. However, some women with POF may experience occasional periods, which could be perceived as irregular.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Pregnancy: Although it might seem obvious, pregnancy should always be ruled out in cases of irregular menstrual periods, as it can have significant implications for health and management.
  • Pituitary Tumors: Tumors in the pituitary gland can affect hormone production, including those that regulate menstruation. While rare, these tumors can have serious health consequences if not diagnosed and treated promptly.
  • Asherman's Syndrome: This condition involves the formation of adhesions or scar tissue in the uterus, often following uterine surgery, which can lead to irregular or absent menstrual periods. It's crucial to diagnose and treat Asherman's Syndrome to prevent infertility and other complications.
• Rare diagnoses:
  • Androgen Insensitivity Syndrome: A rare genetic condition where an individual is genetically male (XY chromosomes) but has a partial or complete inability to respond to androgens, leading to the development of female external genitalia and often presenting with primary amenorrhea or irregular periods.
  • Congenital Adrenal Hyperplasia: A group of inherited disorders that affect the adrenal glands, leading to hormone imbalances. Some forms of CAH can cause irregular menstrual periods due to the excessive production of androgens.
  • Turner Syndrome: A genetic disorder that affects females, characterized by the partial or complete absence of one X chromosome. It can lead to ovarian dysgenesis, resulting in irregular or absent menstrual periods.