Differential Diagnosis for Secondary Amenorrhea
Single Most Likely Diagnosis
- Polycystic Ovary Syndrome (PCOS): This is a common endocrine disorder in women of reproductive age, often presenting with irregular menstrual cycles, which can progress to secondary amenorrhea. The patient's age and the absence of pregnancy make PCOS a plausible diagnosis.
Other Likely Diagnoses
- Hypothyroidism: Thyroid dysfunction can disrupt menstrual cycles, leading to amenorrhea. It's a common condition that can be easily screened for and treated.
- Stress or Weight-Related Amenorrhea: Significant psychological stress or changes in weight (either gain or loss) can affect the hypothalamic-pituitary-gonadal axis, leading to amenorrhea.
- Hyperprolactinemia: Elevated prolactin levels can suppress gonadotropin-releasing hormone (GnRH) secretion, resulting in amenorrhea. This could be due to a prolactinoma or other causes.
Do Not Miss Diagnoses
- Pituitary Tumor: Although less common, a pituitary tumor (such as a prolactinoma) can cause amenorrhea by disrupting normal pituitary function. Missing this diagnosis could lead to significant morbidity.
- Premature Ovarian Failure (POF): Also known as premature ovarian insufficiency, this condition involves the loss of ovarian function before the age of 40. It's crucial to diagnose to address fertility and menopausal symptom management.
- Asherman Syndrome: This condition, characterized by intrauterine adhesions, can lead to amenorrhea. It often follows uterine surgery, such as a dilation and curettage (D&C).
Rare Diagnoses
- Congenital Adrenal Hyperplasia (CAH): A group of inherited disorders that affect the adrenal glands, CAH can lead to hormonal imbalances that might cause amenorrhea, although it's more commonly diagnosed in infancy or childhood.
- Sheehan Syndrome: A rare condition involving postpartum necrosis of the pituitary gland, typically following severe postpartum hemorrhage. It could potentially cause amenorrhea but is less likely in a patient without a history of recent childbirth.
- Autoimmune Disorders: Certain autoimmune conditions, such as autoimmune oophoritis or orchitis, can lead to gonadal failure and amenorrhea, though these are rare.