Menstruation: the fifth vital sign in women of reproductive age

Menstruation is a vital sign of women's health; every woman typically experiences 400 to 450 ovulations and 7 years of menstruation over her lifetime.Abnormal uterine bleeding (AUB) affects up to one-third of women during their reproductive years, impacting quality of life, but menstrual complaints are frequently under-reported.Healthy menstruation is determined by non-modifiable factors (age, ethnicity, and genetics) and modifiable factors (smoking, diet and nutrition, exercise, body weight, stress, gynaecological disorders, and systemic disorders).Healthy menstruation encompasses regularity, normal flow and duration, and the absence of dysmenorrhoea.These characteristics are indicators of a healthy reproductive system and overall well-being.AUB is a leading cause of iron deficiency and anaemia, particularly in women of reproductive age.In Hong Kong, 17.5% of women of reproductive age have iron deficiency.Comprehensive evaluation of menstruation is crucial in managing anaemia.Femtech (female technology) facilitates menstrual education and personalised health management.Recognition of menstruation as the fifth vital sign in women of reproductive age is important to overall health assessment.Early detection and management of AUB, along with related complications, namely iron-deficiency anaemia, can optimise women's health outcomes.