Most women notice at some point that their period is late, early or unpredictable. An occasional change is common and often harmless, but periods that are repeatedly irregular, very delayed or absent can signal an underlying hormonal, medical or structural problem, and they can also affect your chances of conceiving. Finding the cause is usually the first step to the right treatment.
This page explains what counts as a regular cycle, the common causes of irregular or delayed periods, when to see a doctor, how the problem is diagnosed and how it is treated. It is general educational information. The right plan can only be decided after a personal consultation.
The menstrual cycle is counted from the first day of one period to the first day of the next. In most adult women the cycle lasts between about 21 and 35 days, and bleeding usually lasts for around two to seven days. Cycles can be a few days shorter or longer from month to month, and they are often irregular in the first years after periods begin and in the years approaching menopause.
Doctors use several terms to describe menstrual irregularity:
Please consult a gynaecologist if:
Understanding the hormonal, lifestyle, medical, and structural factors that can disrupt your menstrual cycle.
A delayed period in a woman who is sexually active should first be checked with a pregnancy test. Pregnancy is the most common reason for a missed period, and an early scan is needed if there is pain or bleeding.
PCOS is one of the most common causes of irregular periods. Ovulation happens infrequently or not at all, which leads to long, unpredictable cycles. It may be accompanied by acne, excess facial or body hair, scalp hair thinning or weight gain.
An underactive or overactive thyroid can disturb the cycle, leading to delayed, scanty, heavy or missed periods.
High levels of prolactin, a hormone linked to milk production, can interfere with ovulation and stop periods. It may be caused by a small pituitary growth, medicines, thyroid disease or stress.
Significant stress, rapid weight loss or gain, low body weight, restrictive diets and very intense exercise can switch off the signals from the brain that drive ovulation, causing missed or absent periods.
Approaching menopause, cycles become irregular as ovulation becomes less predictable. When the ovaries stop functioning normally before the age of 40, a condition called premature ovarian insufficiency, periods may become irregular or stop, and this needs medical evaluation.
Hormonal contraceptives, emergency contraception, certain psychiatric medicines and other drugs can affect the cycle. Periods may take time to settle after stopping hormonal contraception.
Fibroids, polyps, adenomyosis and, in some women, scarring inside the uterus after procedures or infection can cause irregular or abnormal bleeding or very light periods.
Chronic illness, diabetes, severe anaemia, eating disorders and some other hormonal conditions can also affect menstruation.
A step-by-step clinical evaluation combining your medical history, blood tests, and imaging to pinpoint the exact cause.
Your doctor will ask about your cycle pattern, the amount and duration of bleeding, pain, weight changes, stress, exercise, medicines, past pregnancies and family history. A general and, where appropriate, pelvic examination is done.
A urine or blood pregnancy test is usually the first step if there is any chance of pregnancy.
Depending on your history, blood tests may include thyroid function, prolactin, reproductive hormones such as FSH, LH and estradiol, AMH, androgens, blood sugar and a haemoglobin check. The timing of some tests depends on the cycle phase.
An ultrasound examines the uterus and ovaries, looks for fibroids, polyps or cysts, measures the endometrial thickness, and checks for features of PCOS.
Hysteroscopy, an endometrial sample or other tests may be recommended if there is heavy or abnormal bleeding, suspected structural problems, or when the lining needs to be examined.
Treatment depends on the cause, your age, whether you wish to conceive and your general health.
Lifestyle Measures: Achieving a healthy weight, balanced nutrition, regular exercise, adequate sleep and stress management can restore regular ovulation in many women, particularly those with PCOS or weight-related irregularity. Women who are underweight or exercise intensively may need to increase nutrition or reduce training.
Treating the Underlying Condition: Thyroid disorders and raised prolactin are treated with appropriate medicines, which often restore regular cycles. Fibroids, polyps and other structural problems may need medical or surgical treatment, including hysteroscopic or laparoscopic procedures where suitable.
Hormonal Treatment to Regulate Periods: For women who do not wish to conceive, hormonal medicines may be used to regulate the cycle and protect the uterine lining. In women who ovulate rarely, regular shedding of the lining is important, since long periods without bleeding can lead to thickening of the lining that needs evaluation. Your doctor will choose the medicine according to your age, symptoms and health.
Treatment When You Want to Conceive: If you are trying to conceive, treatment focuses on achieving ovulation. This may involve lifestyle changes, treatment of thyroid or prolactin problems and, where needed, ovulation-inducing medicines with ultrasound monitoring, followed by IUI or IVF in selected situations. Please see our pages on ovulation study and monitoring and on female infertility.
Counselling and Follow-Up: Periods may take a few cycles to settle after treatment. Regular follow-up helps to check that the treatment is working and to adjust it as needed.
Irregular Periods and Fertility: Irregular periods often mean irregular ovulation, which can make conception harder and less predictable. This does not mean that you cannot become pregnant. Many women with irregular cycles conceive after the cause is identified and treated. If you are planning pregnancy, it is sensible to seek advice early, particularly if you are over 35.
Dr. Sunita Arora is an obstetrician, gynaecologist and fertility specialist with more than 23 years of experience. She holds an MBBS from Lady Hardinge Medical College, New Delhi, and an MD in Obstetrics and Gynaecology from UCMS and GTB Hospital, and she is a Fellow of the Indian College of Obstetricians and Gynaecologists (FICOG) and a Fellow of the International College of Surgeons (FICS). She completed a fellowship in Reproductive Medicine at D.Y. Patil University, Mumbai, and received IVF training at RMA, Mount Sinai, New York.
Her practice covers general gynaecology, pregnancy care, infertility and endoscopic surgery, and patients are guided through each step in clear, plain language.
If your periods are irregular, delayed or absent, or you are planning a pregnancy, a careful evaluation can identify the cause and guide treatment.
She consults at Safdarjung Enclave and is also associated with Fortis La Femme, Greater Kailash II, serving women across South Delhi, including Greater Kailash, Green Park, Hauz Khas and nearby areas.
Dr Sunita Arora Fertility and Gynae Clinic
Fortis La Femme, South Delhi
Book an appointment with Dr. Sunita Arora to discuss your concerns, and bring any previous reports and scans.
Find answers to common questions about late or irregular periods, stress, PCOS, fertility, and treatment options.
Medical disclaimer: This page is for general educational purposes and does not replace personalised medical advice, diagnosis or treatment. Please consult a qualified doctor about your own health. If you have severe abdominal pain, heavy bleeding, fainting or fever, seek urgent medical care.