Irregular Periods in Perimenopause: What's Normal and When to Get Checked

Irregular periods are usually the first sign of perimenopause. Cycles may become shorter or longer, periods may be heavier, lighter or skipped, and spotting can happen. This happens because ovulation becomes less predictable. Some changes need checking, though: bleeding after sex or between periods, very heavy or prolonged bleeding, or any bleeding a year after your last period.

What do irregular periods look like in perimenopause?

Changes vary from person to person and can shift over time. Common patterns include:

• Shorter cycles, so periods come closer together, which is often seen early in perimenopause
• Longer cycles or skipped periods, which become more common later
• Heavier or longer periods, sometimes after a skipped month. See heavy bleeding.
• Lighter periods or spotting
• Brown or dark blood, particularly at the start or end of a period
• Unpredictability, with no two cycles quite the same

ACOG notes that during perimenopause, periods may become shorter or longer, the days between them may increase or decrease, and bleeding may become heavier or lighter.

Why do periods become irregular?

During perimenopause, the ovaries respond less consistently to signals from the brain. Some months the ovaries release an egg; other months they don’t. Estrogen fluctuates, sometimes rising higher than usual, while progesterone falls in cycles without ovulation.

Without the regular rise and fall of progesterone that follows ovulation, the womb lining can build up unevenly and shed unpredictably. That’s why periods can be late, early, heavy, light or skipped. See hormone changes during perimenopause.

How do periods change through the stages?

The STRAW+10 research framework describes two stages of perimenopause based on bleeding patterns:

Not everyone follows this neatly. Research summarized by the US Centers for Disease Control and Prevention found 12% to 25% of women have little or no change in cycle length before their final period. See the stages of menopause.

What else can cause irregular periods?

Perimenopause is common in the 40s, but other causes should be considered, especially if changes are sudden or unusual:

• Pregnancy. Take a test if there’s any chance. You can still get pregnant in perimenopause. See pregnancy during perimenopause.
• Thyroid problems
• Hormonal contraception, HRT or other medicines
• Fibroids, polyps or adenomyosis in the womb
• Polycystic ovary syndrome (PCOS)
• Significant weight change, stress or intense exercise
• Changes in the womb lining, such as thickening (endometrial hyperplasia), which is more likely with prolonged or heavy bleeding
• Infections

See perimenopause or something else.

Which changes need checking?

Many changes are expected, but some need assessment.

See a clinician promptly if you have:

• Bleeding after sex
• Bleeding or spotting between periods that keeps happening
• Very heavy bleeding: soaking through one or more pads or tampons every hour for several hours, needing to double up protection, or passing large clots
• Periods lasting more than 7 days
• Periods coming more often than every 21 days
• Any bleeding 12 months or more after your last period
• Heavy bleeding with tiredness, breathlessness or dizziness, which may signal anemia

Seek emergency care if you’re soaking through pads or tampons every hour for more than 2 hours and also have chest pain, breathlessness or dizziness.

The Australasian Menopause Society notes that heavy bleeding, bleeding after a long gap, and prolonged bleeding of any amount should be investigated. Any bleeding after menopause also needs checking.

What will a clinician assess?

A clinician will usually ask about:

• Your cycle pattern, bleeding and any spotting. A written record helps.
• Whether you could be pregnant
• Contraception, HRT or other medicines
• Other symptoms, such as hot flashes, pain or tiredness

Depending on your symptoms, they may suggest:

• A pregnancy test
• Blood tests, such as a blood count to check for anemia, and thyroid function
• A pelvic examination and cervical screening if due
• An ultrasound scan to look at the womb lining and check for fibroids or polyps
• Sampling of the womb lining in some cases

For people over 45 with irregular periods and other menopause symptoms, NICE advises no hormone tests are needed to identify perimenopause.

How can irregular periods be managed?

Treatment depends on what bothers you and your contraception needs:

• The hormonal IUD reduces heavy and irregular bleeding, provides contraception, and can later form part of HRT.
• Combined hormonal contraception can regulate bleeding and ease symptoms for people under 50 who can safely use it.
• The progestogen-only pill helps some people, although some have more frequent bleeding.
• Hormone therapy can regulate bleeding with a cyclical regimen in perimenopause.
• Tranexamic acid and anti-inflammatory medicines can reduce heavy bleeding when it happens.

See heavy bleeding for more detail.

Practical steps that may help

• Keep a record of bleeding days, flow and spotting. Our private Symptom Explorer can help.
• Carry supplies, such as period pants, pads or a menstrual cup, since periods can arrive unexpectedly.
• Use contraception if you don’t want to become pregnant.
• Eat iron-rich foods if your periods are heavy, and ask about an iron test if you feel tired.

Your period record: what to note

A simple record makes it far easier to tell expected changes from ones that need checking:

Our private Symptom Explorer can store this for you and prepare a summary for your appointment.

Common myths about irregular periods

"Irregular periods mean I can’t get pregnant." You can, until guidance says you can stop contraception.

"Any bleeding in perimenopause is normal." Many changes are expected, but bleeding after sex, between periods, very heavy bleeding, or bleeding after menopause needs checking.

"If my periods are regular, I’m not in perimenopause." Some people have little change in their cycle before their final period, and notice other symptoms first.

"Irregular periods always mean menopause is close." Irregular cycles can continue for several years before the final period.

Questions to ask at your appointment

1. Are my period changes typical of perimenopause?
2. Do I need any tests, such as a scan or blood count?
3. What can I do about unpredictable or heavy bleeding?
4. Do I still need contraception, and which type would help my bleeding?
5. How will I know when I’ve reached menopause? See how to know when menopause has started.

Related symptoms

Heavy bleeding · Hot flashes · Fatigue

See the early signs of perimenopause.

Frequently asked questions

Is it normal to have two periods in a month during perimenopause?

Shorter cycles are common in perimenopause. However, periods more often than every 21 days, or bleeding between periods, should be checked.

Can you skip periods and then have them again?

Yes. Periods can stop for months and then return. This is why menopause is only confirmed after 12 months without a period.

Why is my period brown in perimenopause?

Brown blood is usually older blood that has taken longer to leave the body, and it’s common with lighter or irregular periods. Persistent unusual discharge or bleeding should be checked.

Can I still get pregnant with irregular periods?

Yes. Ovulation can still happen unpredictably, so use contraception until guidance says you can stop.

Should I stop hormonal contraception to find out if I’m in perimenopause?

Not necessarily. UK guidance from the Faculty of Sexual and Reproductive Healthcare advises that clinicians focus on your symptoms and needs rather than hormone levels. Many contraceptive methods can be continued until contraception is no longer needed. Discuss your situation before stopping.

What does spotting after sex mean?

Bleeding after sex can have simple causes, such as vaginal dryness, but it can also be caused by problems with the cervix or womb lining. It should always be checked.

References

1. ACOG: Perimenopausal bleeding and bleeding after menopause
2. ACOG: Abnormal uterine bleeding
3. ACOG: Heavy menstrual bleeding
4. NHS: Symptoms of menopause and perimenopause
5. Harlow SD et al. Executive summary of STRAW+10 (2012), via ASRM
6. CDC Stacks: Menstrual cycle changes as women approach the final menses
7. Endocrinology of the menopause (review)
8. Australasian Menopause Society: Bleeding in perimenopause, postmenopause and on MHT
9. NICE guideline NG23: Menopause, identification and management
10. FSRH Contraception Choices: Perimenopause and menopause
11. FSRH guideline: Contraception for women aged over 40 years
12. My Menopause Centre: Period changes (treatment options)
13. Mayo Clinic Press: Menopause symptoms? It could be a copycat

Editorial status: evidence-based educational article. Last evidence check: September 10, 2026.