Possible causes
- Stress – under strain the brain suppresses the control of ovulation.
- Low energy availability – strict diets and lots of training can suppress ovulation.
- Polycystic ovary syndrome – often associated with insulin resistance, acne and excess body hair.
- Thyroid and prolactin – their disorders can lengthen or stop the cycle.
- Perimenopause – after 40 the cycle naturally becomes irregular.
- Weight change and contraception – rapid weight loss or gain, or stopping hormonal contraception.
What to check
- LH, FSH and estradiol – ideally at the start of the cycle, as advised by your gynaecologist.
- Progesterone – in the second half of the cycle to confirm ovulation.
- TSH and prolactin – the basics for an irregular cycle.
- Testosterone, SHBG, DHEA-S, glucose and insulin – if polycystic ovary syndrome is suspected.
What helps
- Enough energy – with an active life, don't eat too little, especially carbohydrates and fats.
- Sensible training – a mix of strength and movement without chronic overload.
- Regular sleep and daylight – a stable daily rhythm supports the hormonal rhythm.
- Eating for insulin resistance – protein, fibre, fewer fast sugars, movement after meals.
- Cycle tracking – an app or calendar gives you and your doctor important information.
When to see a doctor
See a gynaecologist if your period has been absent for more than three months, you bleed very heavily or between periods, have severe pain, could be pregnant, or if acne, excess body hair or nipple discharge appear.