Amenorrhoea is the medical term for the absence of menstrual periods in women of reproductive age.

Types of Amenorrhoea

1. Primary Amenorrhoea

   Primary amenorrhoea is defined as the failure to start menstruating by the age of 16 when other normal secondary sexual characteristics are present.

   • Alternatively, it can be defined as the lack of menstruation by age 14 if typical secondary sexual characteristics are absent.

   Causes of Primary Amenorrhoea

   1. Significant Weight Loss: A substantial decrease in body mass, potentially from restrictive diets or eating disorders, can disrupt the hormonal equilibrium necessary for menstruation.

   2. Intense Exercise or Stress: High levels of physical exertion or prolonged stress may interfere with the regular hormonal fluctuations needed for the menstrual cycle.

   3. Constitutional Delay (Family History): A delayed onset of menstruation, if present in family history, may indicate a genetic predisposition to later menarche.

   4. Imperforate Hymen: An imperforate hymen, where this membrane at the vaginal opening is completely closed, can block the outflow of menstrual blood, leading to its retention within the vagina.

   5. Eating Disorders: Conditions such as anorexia nervosa or bulimia can result in nutritional deficiencies that negatively impact reproductive hormone production.

   6. Thyroid Gland Issues: Dysfunction of the thyroid gland can disrupt the delicate hormonal balance required for consistent menstrual cycles.

   7. Genetic Factors: Certain genetic conditions or chromosomal irregularities can affect reproductive system development, thus delaying the start of menstruation.

   8. Chronic Diseases: Long-lasting illnesses impacting various bodily systems can disturb the hormonal equilibrium essential for menstruation.

   9. Anatomical Abnormalities: Structural irregularities within the reproductive organs, such as issues with the uterus or ovaries, can impede the typical menstrual process.

   10. Hormonal Imbalances: Abnormal levels of hormones like FSH (Follicle Stimulating Hormone) or LH (Luteinizing Hormone), which are crucial for puberty and menstruation, can be a cause.

   11. Tumours or Growths: Non-cancerous or cancerous growths affecting the ovaries or pituitary gland can disrupt hormonal regulation.

   12. Medication Side Effects: Prolonged use or sudden cessation of certain medications, for example, hormonal contraceptives, can have an impact on menstrual regularity.

   13. Celiac Disease: Celiac disease, which impairs nutrient absorption, can lead to hormonal imbalances that affect menstruation.

2. Secondary Amenorrhoea

   Secondary amenorrhoea is defined as the cessation of menstruation for 6 months or more in women who previously had regular menstrual cycles.

   • It is crucial to exclude pregnancy when diagnosing secondary amenorrhoea.

   Causes of Amenorrhoea

   Normal Physiology:

   • Pregnancy: During gestation, elevated levels of estrogen and progesterone maintain the uterine lining, resulting in amenorrhoea.

   • Lactation (Breastfeeding): Post-delivery, prolactin, a hormone involved in milk production, is released in high quantities, which can partially suppress LH production and prevent ovulation, leading to amenorrhoea.

   Abnormal Physiology:

   • Functional Hypothalamic Amenorrhoea: Reduced levels of FSH and LH due to hypothalamic dysfunction can cause secondary amenorrhoea. This condition is often diagnosed after ruling out other organic causes and is characterized by irregular GnRH secretion, low or normal LH levels, absent follicle development, and lack of ovulation.

   • Premature Ovarian Insufficiency (Failure): Accelerated depletion and impaired function of ovarian follicles can lead to premature ovarian insufficiency, resulting in secondary amenorrhoea.

   • Contraceptive Pills: Hormonal birth control methods can influence menstrual cycles and lead to secondary amenorrhoea in some cases.

   • Malnutrition: Insufficient nutritional intake can disrupt hormone levels and result in secondary amenorrhoea.

   • Psychological Stress: Emotional stress and psychological factors can affect hormonal balance, potentially causing secondary amenorrhoea.

   • Infections (e.g., Pelvic Inflammatory Disease – PID): Infections such as PID can disrupt normal reproductive function, leading to secondary amenorrhoea.

   • Polycystic Ovary Syndrome (PCOS): PCOS can cause hormonal irregularities, leading to irregular periods and potentially secondary amenorrhoea.

   • Emergency Contraceptive Pills: These pills can alter hormone levels and disrupt the menstrual cycle, potentially leading to secondary amenorrhoea.

   • Diabetes Mellitus: Poorly managed diabetes can affect hormone levels and lead to secondary amenorrhoea.

   • Resistant Ovary Syndrome: This condition can cause hormonal imbalances and disrupt the menstrual cycle, potentially causing secondary amenorrhoea.

   • Radiation Exposure: High doses of radiation can impair normal ovarian function, leading to secondary amenorrhoea.

   • Medications: Certain drugs, particularly hormonal contraceptives, can affect hormone levels and cause secondary amenorrhoea.

   • Head Trauma: Traumatic head injuries can disrupt normal hormonal regulation, potentially leading to secondary amenorrhoea.

   • Debilitating Illnesses: Conditions such as tuberculosis (TB), HIV/AIDS, and diabetes mellitus can disrupt normal hormonal balance, potentially leading to secondary amenorrhoea.

   • Tumours: Tumours in the pituitary gland, hypothalamus, ovaries, or uterus can disrupt normal hormonal function, leading to secondary amenorrhoea.

   • Early Menopause (Premature Ovarian Failure): Menopause occurring earlier than expected can cause secondary amenorrhoea.

   • Idiopathic: In some instances, the cause of secondary amenorrhoea remains unknown or cannot be identified.