Irregular periods are menstrual cycles that are shorter than 21 days, longer than 35 days, vary widely from month to month or stop for several months, and they are commonly caused by hormonal changes, PCOS, thyroid problems, stress, weight changes, perimenopause or conditions of the uterus. Occasional variation is normal, especially in the teenage years and before menopause. You should see a gynecologist if your periods stay irregular for more than a few months, stop without pregnancy, are very heavy or painful, or if you have bleeding between periods or after sex.
This article explains what a normal cycle looks like, the common causes of irregular periods, how they are evaluated and when to seek medical advice.
What Is a Normal Menstrual Cycle?
A menstrual cycle is counted from the first day of one period to the first day of the next. In adults, a typical cycle lasts between 21 and 35 days, with bleeding for 2 to 7 days. Small changes of a few days from month to month are common. Each woman’s pattern is a little different, so tracking your own cycle helps you notice changes.
Signs That Your Periods Are Irregular
- Cycles shorter than 21 days or longer than 35 days
- Cycle length changing by more than 7 to 9 days from month to month
- Missing three or more periods in a row without pregnancy
- Bleeding lasting more than 7 days
- Very heavy bleeding, such as changing pads every one to two hours or passing large clots
- Spotting or bleeding between periods or after intercourse
Common Causes of Irregular Periods
Polycystic ovary syndrome (PCOS)
PCOS is a hormonal condition that affects ovulation. Along with irregular or delayed periods, it may cause acne, excess hair growth, hair thinning and weight gain. Learn more on our PCOD/PCOS management page.
Thyroid disorders
Both an underactive and an overactive thyroid can change cycle length and flow. A simple blood test can check thyroid function.
High prolactin
Raised prolactin levels can interfere with ovulation and cause missed periods. Sometimes there may be milky discharge from the breasts.
Stress, weight change and exercise
Emotional stress, sudden weight loss or gain, eating disorders and very intense exercise can affect the brain hormones that regulate the cycle.
Puberty and perimenopause
Irregular cycles are common in the first couple of years after periods start and in the years before menopause, when hormone levels fluctuate.
Uterine conditions
Fibroids, polyps and adenomyosis can cause heavy or prolonged bleeding or bleeding between periods. See our article on uterine fibroids.
Contraceptives and medicines
Hormonal contraceptives, intrauterine devices and some medicines can change bleeding patterns, especially in the first few months of use.
Pregnancy-related causes
A missed or unusual period may be due to pregnancy. Bleeding in early pregnancy needs medical review.
Other medical conditions
Diabetes, bleeding disorders, infections of the reproductive organs and, rarely, problems of the uterine lining can also affect periods.
When Should You See a Gynecologist?
Consider booking a consultation if:
- Your periods remain irregular for three months or more
- You have missed three periods in a row and are not pregnant
- Periods are very heavy, last more than 7 days or cause tiredness or breathlessness
- You have bleeding between periods, after sex or after menopause
- Period pain is severe and affects daily activities
- You have acne, excess hair growth or weight gain along with irregular cycles
- You are trying to conceive and your cycles are unpredictable
Seek urgent care if you have very heavy bleeding with dizziness, fainting or a fast heartbeat, or severe abdominal pain. Our guide on heavy period bleeding explains more.
How Are Irregular Periods Evaluated?
The gynecologist will ask about your cycle pattern, flow, pain, weight changes, medicines, contraception and plans for pregnancy. Keeping a record of your periods for a few months is very helpful. Evaluation may include:
- Pregnancy test
- Thyroid function tests and prolactin
- Other hormone tests such as FSH, LH or testosterone, depending on symptoms
- Complete blood count to check for anaemia
- Blood sugar tests where relevant
- Pelvic ultrasound to look at the uterus and ovaries
- Pap smear if cervical screening is due
Treatment Options
Treatment depends on the cause, your age and whether you plan to become pregnant. Options may include:
- Lifestyle measures: balanced diet, regular physical activity, adequate sleep and stress management
- Treating the underlying condition: for example, thyroid medicines or managing high prolactin
- Hormonal medicines: to regulate cycles or control heavy bleeding, when suitable
- Ovulation support: for women trying to conceive, under medical supervision
- Procedures: for fibroids or polyps, if needed
Avoid starting hormone tablets without a prescription, as they can mask the cause and are not suitable for everyone. Visit our page on menstrual problems treatment for more information.
Tracking Your Cycle
Use a calendar or app to note the first day of each period, how long it lasts, how heavy the flow is and any pain or spotting. This record makes your consultation more useful and helps the doctor spot patterns.
Frequently Asked Questions
What is considered an irregular period?
A cycle is generally considered irregular if it is shorter than 21 days, longer than 35 days, varies a lot from month to month, if bleeding lasts more than 7 days, or if periods stop for three months or more without pregnancy.
Is it normal to have irregular periods in the teenage years?
Yes, some irregularity is common in the first one to two years after periods begin, as hormone cycles mature. If periods remain very irregular after that, are very heavy or absent for months, a check-up is advised.
Can stress cause irregular periods?
Yes. Physical or emotional stress, sudden weight change, intense exercise and illness can affect the hormones that control ovulation, causing late or missed periods.
Can PCOS cause irregular periods?
Yes. PCOS is one of the most common causes of irregular periods in women of reproductive age. It may also cause acne, excess hair growth, weight gain and difficulty conceiving.
Do irregular periods affect fertility?
Irregular periods may mean ovulation is not happening regularly, which can make conception harder. Many underlying causes can be managed, so it is worth consulting a gynecologist if you are planning a pregnancy.
What tests are done for irregular periods?
Common tests include a pregnancy test, thyroid function, prolactin, other hormone tests, blood count and a pelvic ultrasound. The gynecologist chooses tests based on your age, symptoms and history.
Consult Dr. Akula Ramya Krishna at RK Women’s Clinic
If your periods have become unpredictable or are affecting your daily life, a consultation can help identify the cause and the options suitable for you. Dr. Akula Ramya Krishna (MBBS, DNB Obstetrics & Gynecology) is an obstetrician and gynecologist practising in Kasarvadavali, Thane.
- Address: Shop No. 27, Yashraj Park, Kasarvadavali, Thane, Maharashtra
- Phone: +91 85916 13084
You can also book through the contact page.
