Amenorrhea refers to the absence of menstruation in women of childbearing age. It can be divided into two main categories: primary amenorrhea and secondary amenorrhea.

Primary Amenorrhea

This refers to cases where a young woman has not experienced her first menstruation (menarche) by the age of 16. The causes can be genetic, anatomical, or hormonal.

Causes of Primary Amenorrhea:

  • Genetic or Chromosomal Abnormalities:
    For example, Turner syndrome (missing or structurally altered X chromosome).
  • Anatomical Malformations:
    Malformations of the uterus, vagina, or other structures of the reproductive system, such as an absent uterus or vaginal atresia (closure or absence of the vaginal canal).
  • Hormonal Disorders:
    Problems in the hypothalamic-pituitary axis that affect hormone production (e.g., Kallmann syndrome).
  • Androgen Insensitivity Syndrome:
    A condition in which a genetically male child (XY chromosomes) does not develop male sexual characteristics due to androgen receptor dysfunction and is raised as a girl but does not menstruate.

Diagnostics and Treatment:
The treatment of amenorrhea depends on its cause. Diagnosis typically involves taking a medical history, conducting a physical examination, and testing hormone levels. Imaging techniques (such as ultrasound) or genetic tests may also be helpful. Therapy ranges from lifestyle changes (in cases of stress, eating disorders, or excessive exercise) to hormonal treatments and surgical interventions for anatomical abnormalities.

Secondary amenorrhea

Secondary amenorrhea means that a woman who previously had regular menstruation stops having periods for at least 3 months (if cycles were previously regular) or 6 months (if cycles were previously irregular).

1. Physiological causes

  • Pregnancy (most common cause)

  • Breastfeeding (lactational amenorrhea due to high prolactin levels)

  • Menopause (natural cessation of ovarian function)

2. Pathological causes

A. Hypothalamic causes (impaired GnRH secretion)

  • Stress (psychological or physical)

  • Severe underweight / anorexia nervosa

  • Competitive athletics

  • Chronic illnesses

B. Pituitary causes

  • Hyperprolactinemia (e.g., due to prolactinoma, medications such as antipsychotics)

  • Pituitary tumors or infarction (Sheehan’s syndrome)

  • Infiltrative diseases (e.g., sarcoidosis)

C. Ovarian causes

  • Polycystic ovary syndrome (PCOS)

  • Primary ovarian insufficiency (e.g., after chemo-/radiotherapy, autoimmune disease)

  • Turner mosaicism (rare)

  • Infections or surgeries resulting in ovarian loss

D. Uterine causes

  • Asherman’s syndrome (intrauterine adhesions after curettage or infection)

  • Endometrial destruction from radiation

E. Endocrine disorders

  • Thyroid disorders (hypo- or hyperthyroidism)

  • Cushing’s syndrome

  • Adrenal insufficiency

In cases of secondary amenorrhea, pregnancy must always be ruled out first — even in seemingly “unlikely” situations.