Symptoms
What causes irregular periods?
Periods are irregular when the gap between them is under 21 days or over 35. Common causes include puberty, the start of menopause, pregnancy, hormonal contraception, big weight changes, stress and too much exercise. Sometimes PCOS or a thyroid problem is behind it. It is not usually a sign of a problem, but see a GP.
What counts as irregular?
The NHS says the average gap between periods is about 28 days, and it can sometimes be a bit shorter or longer. ACOG also counts cycles where the length varies by more than 7 to 9 days as irregular.
What are the common causes?
- Puberty and the first years of periods.
- The start of menopause, usually between 45 and 55.
- Pregnancy: a missed period is often an early sign.
- Hormonal contraception such as the progestogen-only pill, the injection and the hormonal coil.
- Losing or gaining a lot of weight.
- Stress and anxiety.
- Exercising too much.
Which conditions can cause irregular periods?
PMOS (formerly PCOS) and thyroid problems. ACOG adds that when ovulation doesn’t happen for several cycles, periods can become irregular and sometimes heavy.
How can I tell if my periods are irregular?
Keep track. The NHS says using an app or a diary helps you see if they’re irregular. Day 1 of your cycle is the first day of your period, and the last day is the day before your next one.
Can I get pregnant with irregular periods?
Yes, but it can be harder, because you might not release an egg regularly. If you’re trying, the NHS suggests having sex every 2 or 3 days throughout your cycle. If you don’t want to be pregnant, use contraception: you can’t count on a safe time of the month.
When should I see a doctor?
The NHS says to see a GP if:
- Your periods are irregular.
- Your periods last longer than 7 days.
- You have irregular periods and other symptoms like weight gain, tiredness, hair growth on your face, and dry or oily skin.
- You bleed between periods.
- Your periods are irregular and you’re struggling to get pregnant.
Frequently asked questions
Are irregular periods normal?
They’re common at the start of periods and as menopause nears. Otherwise they’re worth mentioning to a GP.
Does irregular mean the same as late?
Not exactly. A late period is one that comes later than expected. Irregular means the gaps vary a lot or fall outside 21 to 35 days.
Do irregular periods need treatment?
Treatment is not always needed. If it is, it depends on the cause. For example, the combined pill may help make periods more regular if PMOS is the cause.
Sources
Seventh is a free period and cycle tracker for iPhone and iPad, by doogud. This article is general information, not medical advice. If something feels wrong, see a doctor.
