Periods in your 40s: what changes and why
In your 40s, periods often change as perimenopause begins: cycles may get shorter at first, then irregular, and bleeding can become heavier or lighter. PMS may feel stronger. Fibroids, polyps and adenomyosis also become more common and can cause heavy bleeding. Many changes are normal, but bleeding between periods, after sex or soaking through products hourly needs a doctor.
The most common changes
| Change | Why it often happens | Usually normal? |
|---|---|---|
| Shorter cycles (e.g. 28 days becoming 24) | Follicles grow faster as egg supply falls, so you ovulate earlier | Yes, often the first sign |
| Irregular cycles, varying by 7+ days | Ovulation becoming unpredictable: early perimenopause | Yes, but track it |
| Heavier periods | Cycles without ovulation, plus fibroids, polyps or adenomyosis | Common, but treatable and worth checking |
| Lighter or shorter periods | Lower estrogen in some cycles | Usually |
| Skipped periods | Cycles without ovulation; later perimenopause | Yes, once you've ruled out pregnancy |
| Stronger PMS | Bigger hormone swings and lower progesterone | Common; very treatable |
| Spotting before periods | Progesterone falling earlier | Often, but mention it |
ACOG describes it simply: in your 40s, periods may be shorter or longer, the days between may increase or decrease, bleeding may be heavier or lighter, and you may skip periods. For most people these changes are the first stage of perimenopause, which usually starts in the mid-40s.
Heavy periods in your 40s
This is the change that disrupts life most often, and it's very treatable. Heavy bleeding in your 40s can come from hormone swings alone, but also from conditions that become more common with age:
- Fibroids: non-cancerous growths in the muscle of the uterus, which can cause heavy, long periods and pressure.
- Polyps: small growths on the lining that can cause heavy or irregular bleeding and spotting.
- Adenomyosis: lining-like tissue growing into the muscle wall, causing heavy, painful periods. Most common between 40 and 50. See adenomyosis.
- A thickened lining (endometrial hyperplasia): more likely with long cycles without ovulation; needs checking, because occasionally it can lead to cancer.
Heavy periods can also cause iron deficiency, leaving you tired, breathless and foggy, which is easy to blame on age or stress. A simple blood test can check. Treatments include the hormonal IUS, tranexamic acid, anti-inflammatory painkillers and hormonal tablets. More in heavy periods.
PMS and mood in your 40s
Many people notice their premenstrual days get harder in their late 30s and 40s: more irritability, anxiety, low mood or poor sleep before a period. Progesterone tends to fall earlier in perimenopause, while estrogen can swing higher and lower than before, and the brain notices those swings. Life in your 40s is often busy too, with work, children and parents, which leaves less room to absorb a hard week.
See PMS getting worse and perimenopause mood swings.
Pregnancy and contraception in your 40s
Fertility falls through your 40s, but you can still get pregnant while you're having periods, even irregular ones. If you don't want to, keep using contraception: the NHS advises continuing until 2 years after your last period if you're under 50, or 1 year if you're 50 or over. Some methods, like the hormonal IUS, also help heavy bleeding.
What helps
- Track start dates, flow on your heaviest day, and mood. Changes are easier to discuss with numbers. The cycle length calculator shows how your cycles are shifting.
- Get heavy periods treated. You don't have to cope with flooding.
- Check your iron if you're tired.
- Plan around premenstrual days once you know when they fall.
- Move and strength-train. Good for mood, sleep and bones as estrogen starts to fall.
Lulu learns from every cycle you log, so it follows your cycles as they shorten or become irregular. Perimenopause mode is there when you need it, and daily mood check-ins show whether your harder days are moving or growing.
When to see a doctor
See a doctor if you bleed between periods or after sex, if periods come less than 21 days apart, last more than 7 days or need a pad or tampon changed every 1 to 2 hours, if you pass large clots or feel faint or breathless, if you have pelvic pain or pressure, or if mood changes affect your life. Any bleeding 12 months after your last period should always be checked.
Frequently asked questions
Is it normal for periods to get closer together in your 40s?
Yes. Shorter cycles are often the first sign of perimenopause. Cycles under 21 days are worth mentioning to a doctor.
Why are my periods heavier in my 40s?
Cycles without ovulation can build a thicker lining, and fibroids, polyps and adenomyosis become more common. It's treatable.
Can you get pregnant in your 40s with irregular periods?
Yes, as long as you're still ovulating some months. Use contraception if you don't want to conceive. See pregnant during perimenopause.
At what age do periods stop?
The average age of menopause is 51, with most people between 45 and 55. See what age do periods stop.
Sources
- ACOG: Perimenopausal Bleeding and Bleeding After Menopause
- NHS: Heavy periods
- NHS: Fibroids
- NHS: Menopause symptoms
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Perimenopause periods: what's normal and what isn'tPerimenopause periods can come closer together, skip, flood or barely show. What's typical at each stage, coping with heavy bleeding, and when to get checked.Perimenopause: what it is, when it starts and how it feelsPerimenopause explained kindly: what's happening to your hormones, when it usually starts, how long it lasts, how it can feel, and what really helps.
Heavy periods: what counts as heavy and what helpsHow to tell if you have heavy periods: soaking a pad every hour or two, clots, bleeding over 7 days. Causes, treatments that work, and when to get help.
Cycle length calculator: is my cycle normal?Free cycle length calculator: enter the start dates of your last few periods to get your average cycle length and see whether your cycle counts as regular.
Adenomyosis: symptoms, diagnosis and what helpsAdenomyosis explained: heavy, painful periods and a tender, bulky uterus. Who it affects, how it differs from endometriosis, diagnosis and treatment.Why is my PMS getting worse? Common reasons and what helpsPMS getting worse lately? Age, perimenopause, stress, sleep and coming off the pill are common reasons. What helps, and when to ask a doctor about PMDD.