Irregular periods

Irregular periods are menstrual periods that do not follow your usual pattern. They may arrive earlier or later than expected, stop for several months, or change in length or flow.

An occasional change is common. Illness, stress, travel, weight changes, and shifts in routine can affect the hormones that control ovulation—the release of an egg from an ovary. When ovulation changes, the timing of a period can also change.

Periods are often less predictable during the first few years after they begin and as menopause approaches. However, a new or persistent change can also have another cause. Irregular periods are a symptom, not a diagnosis.

If pregnancy is possible, take a pregnancy test when a period is late. Pregnancy is an important cause to check for, even if you use contraception.

Irregular periods can include:

• Periods that come earlier or later than usual
• Skipping one or more periods
• Bleeding for a shorter or longer time
• Flow that becomes much lighter or heavier
• Spotting between periods
• Bleeding after sex
• Cramps or pelvic discomfort that differ from your usual pattern

Keeping a record can help you see whether there is a pattern. Note the first day of bleeding, how long it lasts, how heavy it is, and any pain or spotting.

Bleeding between periods or after sex is not the same as a period arriving early. It is worth discussing with a healthcare professional, especially if it happens more than once.

Normal hormone transitions are a frequent reason. Cycles can be irregular during puberty, after pregnancy, while breastfeeding, and in the years leading up to menopause.

Pregnancy commonly causes a missed period. Light bleeding can sometimes occur in early pregnancy, but bleeding during pregnancy should not automatically be assumed to be a period.

Stress, illness, or routine changes can temporarily affect ovulation. Major weight loss or gain, undernutrition, and intense exercise may have a similar effect.

Hormonal contraception can change bleeding patterns. Pills, injections, implants, and hormonal intrauterine devices may cause spotting, lighter periods, or no periods. Missed doses can also lead to unexpected bleeding.

Polycystic ovary syndrome, often called PCOS, can cause infrequent or unpredictable ovulation. Other possible signs include acne, increased facial or body hair, and difficulty becoming pregnant.

Thyroid conditions can affect the menstrual cycle. The thyroid is a gland in the neck that helps control the body’s use of energy.

Less common causes include high levels of the hormone prolactin, early loss of ovarian function, bleeding disorders, pelvic infection, or medicines that affect hormones or blood clotting. Fibroids and uterine polyps—noncancerous growths in or around the uterus—can cause heavy or irregular bleeding. Changes in the cervix or uterine lining are less common causes.

Seek emergency help if you may be pregnant and have bleeding with severe one-sided pelvic pain, shoulder-tip pain, marked dizziness, or fainting. These can be symptoms of an ectopic pregnancy, in which a pregnancy develops outside the uterus.

Emergency assessment is also appropriate if you soak through a pad or tampon every hour for more than two hours and have dizziness, faintness, chest pain, or shortness of breath.

Contact a healthcare service the same day if pregnancy is possible and you are bleeding, particularly if you also have pelvic pain. Seek prompt advice for very heavy bleeding, worsening pain, fever, or feeling unusually weak.

Arrange a routine appointment if:

• You have missed three periods and are not pregnant
• Your cycles repeatedly become unpredictable
• Bleeding occurs between periods or after sex
• Your periods become much heavier or more painful
• You have tiredness, breathlessness, or other possible signs of anemia
• Irregular periods occur with major weight changes, nipple discharge, or increased facial hair
• You are having difficulty becoming pregnant
• Bleeding returns after menopause

A healthcare professional will ask about your usual cycle, when the change began, bleeding amount, pain, contraception, medicines, pregnancy possibility, and other symptoms. Information about stress, eating, exercise, and weight changes may also help.

The first test is often a pregnancy test. Blood tests may be used to check for anemia, thyroid problems, or particular hormone changes. Not everyone needs every hormone test.

Depending on your symptoms, you may be offered a pelvic examination, testing for sexually transmitted infections, or an ultrasound. An ultrasound uses sound waves to look at the uterus and ovaries.

Some people with persistent or unusual bleeding need a sample taken from the uterine lining. Whether this is appropriate depends on factors such as age, medical history, bleeding pattern, and ultrasound findings.

Treatment depends on the cause, how much the bleeding affects you, and whether you want to become pregnant.

If the change is temporary and tests do not show a concerning cause, monitoring may be all that is needed. Cycles may settle as stress, illness, or routine changes improve.

A clinician may offer hormonal treatment to make bleeding more predictable or reduce heavy flow. Other medicines can reduce bleeding or pain. Thyroid problems, PCOS, infection, anemia, fibroids, or polyps may need specific treatment. Procedures are usually considered only when appropriate for the cause and your preferences.

At home, track your bleeding and symptoms. Keep a record of how often you change period products, rather than relying only on terms such as “heavy.” Eat regular, balanced meals that include iron-containing foods. Ask before taking iron supplements, because they are not needed by everyone and can cause side effects.

If pregnancy is possible, follow the instructions on a home pregnancy test. Speak with a healthcare professional if the result is positive, unclear, or negative but your period remains absent.

A single irregular cycle often returns to your usual pattern. Changes caused by puberty, breastfeeding, contraception, or approaching menopause may continue for months or longer.

When an underlying condition is found, the pattern often improves once that condition is managed. Some causes, including PCOS, may need longer-term follow-up.

Irregular periods do not always mean that you cannot become pregnant. Ovulation may still happen, but it can be difficult to predict. Use contraception if you do not want a pregnancy, even if your periods are infrequent.

Keep follow-up appointments if bleeding continues or treatment does not help. A new change after previously regular cycles deserves review, even if the bleeding is not heavy.

Can stress make my period late?

Yes. Physical or emotional stress can affect the hormones that control ovulation. A pregnancy test is still important if pregnancy is possible.

Does a missed period always mean pregnancy?

No. Pregnancy is one possible cause, along with hormone changes, illness, stress, weight changes, intense exercise, and some medical conditions.

Are irregular periods normal before menopause?

They are common during perimenopause, the transition before menopause. Bleeding that is very heavy, occurs after sex, or returns after menopause still needs assessment.

Can I ovulate without regular periods?

Yes. Ovulation may happen unpredictably, including after a long gap without bleeding. Irregular periods are not reliable contraception.

Should I stop hormonal contraception because of spotting?

Do not stop prescribed contraception without considering pregnancy protection. Check the product instructions and discuss persistent, heavy, or troublesome bleeding with a healthcare professional.