Primary Amenorrhea:
- Gonadal Dysgenesis: Including Turner syndrome (45,X karyotype) and other forms of chromosomal abnormalities.
- Müllerian Agenesis: Also known as Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, characterized by the congenital absence of the uterus and the upper part of the vagina.
- Androgen Insensitivity Syndrome: A condition where an individual is genetically male (46,XY karyotype) but is resistant to male hormones (androgens), leading to the development of female physical traits but no menstruation.
- Hypothalamic Dysfunction: Including functional hypothalamic amenorrhea due to stress, weight loss, excessive exercise, or chronic illness.
- Pituitary Disorders: Such as pituitary tumors or hyperprolactinemia.
- Congenital Adrenal Hyperplasia: A group of genetic conditions limiting hormone production in the adrenal glands.
- Imperforate Hymen: A physical obstruction of menstrual flow.
Secondary Amenorrhea:
- Pregnancy: The most common cause of secondary amenorrhea.
- Polycystic Ovary Syndrome (PCOS): A hormonal disorder causing enlarged ovaries with small cysts.
- Thyroid Dysfunction: Both hyperthyroidism and hypothyroidism can lead to menstrual irregularities.
- Hyperprolactinemia: Elevated levels of prolactin can disrupt menstrual cycles.
- Functional Hypothalamic Amenorrhea: Related to stress, excessive weight loss, or exercise.
- Premature Ovarian Insufficiency: Early depletion of ovarian follicles before the age of 40.
- Cushing’s Syndrome: Excess cortisol production can affect menstrual cycles.
- Medications: Certain drugs, including antipsychotics and antidepressants, can cause menstrual irregularities.
- Chronic Illnesses: Conditions like celiac disease or systemic lupus erythematosus (SLE) may lead to amenorrhea.
- Eating Disorders: Anorexia nervosa and bulimia can disrupt menstrual cycles due to hormonal imbalances associated with extreme weight loss or gain