Differential Diagnosis for Secondary Amenorrhea
Single Most Likely Diagnosis
- Pregnancy: Despite the patient's denial of sexual activity, pregnancy is the most common cause of secondary amenorrhea and must be ruled out. It's possible the patient may not be aware of or may not admit to being sexually active.
Other Likely Diagnoses
- Polycystic Ovary Syndrome (PCOS): This condition is common in women of reproductive age and can cause irregular periods or amenorrhea due to hormonal imbalances.
- Thyroid Dysfunction: Both hypothyroidism and hyperthyroidism can disrupt menstrual cycles, leading to secondary amenorrhea.
- Stress or Weight Changes: Significant stress, weight loss, or weight gain can affect the hypothalamic-pituitary-gonadal axis, leading to amenorrhea.
- Excessive Exercise: Intensive exercise can cause amenorrhea due to the physical stress it places on the body, affecting hormone production.
Do Not Miss Diagnoses
- Pituitary Tumor: Although rare, a pituitary tumor can cause secondary amenorrhea by disrupting the production of hormones that regulate menstrual cycles. Missing this diagnosis could lead to serious health consequences.
- Premature Ovarian Failure: This condition, where the ovaries stop functioning before age 40, can cause secondary amenorrhea and has significant implications for fertility and overall health.
- Adrenal Disorders: Certain adrenal disorders, such as congenital adrenal hyperplasia, can cause amenorrhea due to hormonal imbalances.
Rare Diagnoses
- Asherman's Syndrome: A rare condition where scar tissue forms in the uterus, potentially causing secondary amenorrhea.
- Genetic Disorders: Certain genetic disorders, such as Turner syndrome or androgen insensitivity syndrome, can affect menstrual cycles, though these would likely have been identified earlier in life.
- Hypothalamic Amenorrhea: A condition where the hypothalamus does not produce enough gonadotropin-releasing hormone (GnRH), leading to amenorrhea. This can be due to various factors, including genetic predisposition or certain medical conditions.