Menstrual irregularity (oligomenorrhoea / amenorrhoea)

A regular menstrual cycle is generally 21-35 days long, with bleeding lasting 3-7 days. Variations beyond that — cycles too long apart (oligomenorrhoea), too close together (polymenorrhoea), absent altogether for 3+ months (secondary amenorrhoea), or completely unpredictable — are common gynaecology OPD complaints. Most causes are hormonal and well-treatable.

Common causes

• PMOS (PCOS) — by far the most common cause of irregular cycles in women of reproductive age. Often with acne, unwanted hair growth, weight gain, sometimes difficulty conceiving. We covered this in detail on the PMOS / PCOS page.
• Thyroid disorders — both hypo- and hyperthyroidism can disrupt cycles. Often with other thyroid symptoms (fatigue, weight changes, hair fall).
• High prolactin — can suppress periods. Sometimes from a small pituitary tumour, sometimes from medications.
• Stress and significant weight changes — both rapid weight loss (low body fat) and rapid weight gain can disrupt cycles.
• Perimenopause — irregular cycles starting in the 40s, eventually leading to menopause.
• Structural causes — fibroids, polyps, endometriosis (more commonly cause heavy bleeding than missed periods, but can do both).
• Pregnancy — always worth ruling out in a sexually active woman of reproductive age, even when contraception is in use.

Standard workup

For new irregular periods at Asian Hospital we do: pregnancy test (β-hCG), TSH, prolactin, FSH/LH, testosterone, fasting blood sugar + lipid profile (metabolic screen), pelvic ultrasound. Total runs ₹3,000-5,000. The combination tells us which cause to treat.

Treatment

Treatment depends on cause and goal (regulate cycles vs achieve pregnancy vs treat metabolic risk):

• For PMOS: lifestyle + hormonal therapy (combined OC pill) when pregnancy not the goal; lifestyle + ovulation induction when it is.
• For thyroid: levothyroxine for hypo, antithyroid drugs for hyper.
• For high prolactin: cabergoline if treatment is needed.
• For perimenopause: discussion of options, sometimes hormonal therapy.