Menstrual irregularities are a common experience for adolescent girls, especially in the first few years after their first period.
While some variability in menstrual cycles is normal, unusually heavy or persistently irregular bleeds can sometimes be a sign of underlying health issues.
Abnormal menstrual bleeding refers to any irregularity in the menstrual cycle.
This can include periods that are unusually heavy or light, last longer than usual, or occur between regular periods.
While some degree of irregularity can be normal and common in adolescent girls as the body adapts to new hormone changes, persistent or severe cases might indicate a health problem.
Heavy menses and blood loss can also lead to anaemia, where the body lacks enough red blood cells, causing tiredness and fatigue.
Here are some causes of menstrual irregularities:
During adolescence, the menstrual cycle often starts off irregularly because the hypothalamic-pituitary-ovarian (HPO) hormonal axis, which controls menstruation, is still maturing.
This can lead to variations in the cycle length and flow.
Anovulation occurs when the ovaries don’t release an egg, leading to irregular or heavy bleeding.
This is particularly common during the first year after menstruation begins, as the body adjusts to its new hormonal rhythm.
PCOS is a common condition that affects the ovaries and can cause irregular periods, excessive hair growth and acne.
The exact cause of PCOS is unknown, but it is believed to be caused by a combination of genetic, environmental factors and imbalances in hormone levels.
Most, but not all, people with PCOS have excess weight and there is also a risk of developing metabolic complications such as insulin resistance and diabetes.
Thyroid problems can cause irregular periods.
Hypothyroidism (an underactive thyroid producing too little thyroid hormones) can result in infrequent menses, whereas hyperthyroidism (an overactive thyroid with too much thyroid hormones) can cause frequent and heavy menses.
Prolactin is a hormone that helps with milk production and is high during pregnancy and after childbirth.
High levels of prolactin, though less common, can cause menstrual irregularities.
This condition, called hyperprolactinaemia, can lead to missed periods or irregular bleeding.
Hyperprolactinaemia outside of natural lactation can be caused by pituitary tumours in the brain (prolactinomas), certain medications, hypothyroidism, trauma, chest wall irritation, or conditions affecting the hypothalamus or pituitary gland.
Intense physical activity, underweight, high levels of stress and eating disorders such as anorexia nervosa and bulimia, can disrupt menses flow.
Bleeding disorders such as von Willebrand disease and platelet function disorders impair the blood’s ability to clot properly, leading to prolonged or heavy menstrual bleeding.
Pregnancy must be excluded in sexually-active teenagers with secondary amenorrhoea (no period) early in the evaluation.
Important signs
While some degree of irregularity is typical during adolescence, certain patterns should prompt a visit to the doctor.
These include:
If a girl hasn’t started menstruating by age 15 or within three years of developing breasts (i.e. primary amenorrhoea).
Missing periods for three consecutive months (i.e. secondary amenorrhoea).
Menstrual cycles that are consistently shorter than 21 days or longer than 45 days, or cycles that vary widely in length, may indicate hormonal imbalances.
Periods that are excessively heavy – i.e. requiring frequent changes of sanitary products every one or two hours, contains blood clots or lasting more than seven days – could suggest menorrhagia.
Bleeding or spotting between periods might signal hormonal issues or other underlying conditions.
Painful periods that interfere with daily activities (i.e. dysmenorrhoea) should be evaluated by a healthcare provider.
Diagnosis and treatment
When adolescents experience abnormal menstrual bleeding, doctors will typically perform a thorough evaluation.
This usually includes taking a medical history, which would cover detailed history of menstrual cycles, weight changes and any related symptoms; conducting a physical examination; and doing tests like blood tests to check for anaemia or hormonal imbalances, and imaging tests like ultrasounds, to assess the ovaries and uterus.
In cases of secondary amenorrhoea, pregnancy must be excluded if there are no other apparent causes.
The treatment options depend on the underlying cause, for example:
If the menstrual bleeding is severe, treatment might include iron supplements to address anaemia, or other medications to control bleeding, such as tranexamic acid or non-steroidal anti-inflammatory drug (NSAIDS).
A blood transfusion will likely be needed in extreme cases where the blood loss is severe enough to cause symptomatic anaemia with significant symptoms such as dizziness or shortness of breath, or haemodynamic instability with low blood pressure or rapid heart rate.
Hormonal pills can help regulate menstrual cycles by balancing hormone levels.
If hypothyroidism is present, thyroid hormone replacement with L-thyroxine is necessary.
If hyperthyroidism is present, first-line therapy is anti-thyroid medications such as carbimazole or methimazole, to lower the thyroid hormones.
Depending on the underlying cause, medications to lower prolactin levels might be prescribed if elevated prolactin is identified.
Treatment for adolescents with eating disorders such as anorexia nervosa focuses on restoring healthy body weight through nutritional rehabilitation, psychology and family support.
Restoration of normal body weight normalises hormone levels and menstrual cycles without the need of medications.
While menstrual irregularities during adolescence are common as the body adjusts to new hormonal levels, it is essential for parents to bring their daughters to seek medical advice if symptoms are severe or persistent to enable early identification and treatment of any underlying health issues.
Dr Jeanne Wong Sze Lyn is a consultant paediatrician and paediatric endocrinologist. For more information, email starhealth@thestar.com.my The information provided is for educational purposes only and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
Source of editorial content by The Star, www.thestar.com.my/lifestyle/health/hormones-and-kids/2024/09/10/when-your-girl-has-unusual-menstrual-bleeding
