Irregular Periods: Causes, Workup and When to See a Doctor

• A normal adult cycle runs 24-38 days, with bleeding lasting 2-8 days; month-to-month variation of up to about a week is fine.
• PCOS is the single most common cause in Indian women, followed by thyroid disease and high prolactin — all confirmed by simple blood tests.
• Irregular periods reflect ovulation and hormonal health; ignoring them can compound fertility, metabolic and endometrial risks over time.
• Always rule out pregnancy first if you could be pregnant — a home test costs ₹50-150 and is over 99% accurate when used correctly.
• See a doctor if cycles are persistently shorter than 24 or longer than 38 days, absent for over 90 days, very heavy, or bleeding occurs after sex or after menopause.
• A basic workup (pregnancy test, TSH, prolactin, pelvic ultrasound) usually costs ₹2,000-5,000 and finds a clear cause in most women.

A normal menstrual cycle in an adult is 24 to 38 days long, measured from the first day of one period to the first day of the next. Bleeding usually lasts 2 to 8 days. The old idea that exactly "28 days" is the only healthy pattern is a myth — a month-to-month swing of up to about 7-9 days is clinically normal. Your cycle is considered irregular when it falls consistently outside this range or when the length jumps around unpredictably from month to month.

Irregularity shows up in a few recognisable patterns: cycles shorter than 24 days (frequent periods), cycles longer than 38 days (infrequent periods, or oligomenorrhoea), or no bleeding for more than 90 days, called secondary amenorrhoea. Bleeding can also be abnormal in volume or timing — very heavy menstrual bleeding that soaks a pad every 1-2 hours, unusually short periods of 1-2 days, periods dragging on past 8 days, or spotting between periods. Each pattern points towards a different group of causes.

Context matters. In the first 2-3 years after your first period the brain-ovary signalling system is still maturing, so erratic cycles in a teenager are usually a normal phase that settles by about age 18. In the early-to-mid 40s, cycles naturally become irregular as perimenopause begins. Pregnancy and breastfeeding also pause periods. Outside these windows, persistent irregularity deserves a proper explanation rather than being dismissed.

The simplest first step is to track. A paper calendar or a cycle app, recording your exact start dates, flow (how many pads you use on your heaviest day) and any symptoms like acne, hair changes or pain, gives your doctor far more to work with than memory. This is especially useful in India, where iron-deficiency anaemia — which affects more than half of women per NFHS-5 — can quietly alter flow and energy. Think of your cycle as a vital sign that reflects your overall health.

Polycystic ovary syndrome (PCOS) is the leading cause of irregular periods in Indian women from the teens through to the 40s. Indian studies and ICMR data suggest a prevalence ranging widely from roughly 9% to over 20% depending on the population studied and the criteria used. The underlying mechanism is chronic anovulation — the ovaries do not release an egg regularly. Raised luteinising hormone (LH), excess androgens (male-type hormones) and, in many women, insulin resistance prevent a follicle from maturing, so the cycle stretches out to 60 or 90 days or skips entirely.

Beyond irregular cycles, PCOS often shows up as persistent acne, scalp hair thinning, and hirsutism — excess hair on the chin, upper lip or chest. Weight tends to settle around the abdomen, and some women develop acanthosis nigricans, dark velvety patches around the neck or underarms that are a sign of insulin resistance, not poor hygiene. A family history of PCOS or type 2 diabetes raises the risk, and the typical Indian diet, heavy in white rice and refined wheat (maida), can worsen the underlying insulin resistance.

Diagnosis uses the Rotterdam criteria, which require at least two of three features: irregular or absent ovulation; clinical or blood signs of high androgens (visible hirsutism or raised testosterone); and polycystic-appearing ovaries on ultrasound. A pelvic or transvaginal ultrasound typically costs ₹1,200-3,500. Doctors increasingly recognise "lean PCOS" — women with a normal BMI who still have the metabolic and hormonal picture — so a normal weight does not rule it out.

Management is layered. Even a 5-10% reduction in body weight can restore ovulation. A practical Indian approach swaps polished rice for millets (ragi, jowar, bajra), adds protein through dal and paneer, and limits sweets — covered in detail in our PCOS diet plan for Indian women. Doctors often prescribe metformin or inositol to tackle insulin resistance, and combined oral contraceptive pills when cycle control or acne and hirsutism are the priority. PCOS is a long-term metabolic condition, not just a period problem: untreated, it raises the risk of type 2 diabetes and, through chronically unopposed oestrogen, endometrial hyperplasia.

For a full overview of medication, lifestyle and fertility pathways, see PCOS treatment options in India.

Thyroid disease is the second most common hormonal cause of irregular periods in Indian women, who are several times more likely than men to be affected. An underactive thyroid (hypothyroidism) often causes heavy or frequent periods, because thyroid hormone is needed for normal ovulation and for maintaining the uterine lining. Its other symptoms — fatigue, weight gain, constipation, cold intolerance, dry skin and "brain fog" — are easy to dismiss as a busy schedule, which is why it often goes undiagnosed for years.

An overactive thyroid (hyperthyroidism) tends to do the opposite, causing light or absent periods alongside weight loss despite a good appetite, palpitations and anxiety. The screening test for both is TSH (thyroid-stimulating hormone), which costs roughly ₹250-450 at most labs; an abnormal result is followed up with Free T3 and Free T4. Thyroid health matters even more before and during pregnancy, so it is a standard early test. You can read more on recognising the signs of thyroid problems in Indian women.

High prolactin (hyperprolactinaemia) is the next thing to check. Prolactin is the hormone that drives milk production and rises naturally in pregnancy and breastfeeding. When it rises at other times it suppresses the signals that trigger ovulation, leading to skipped or widely spaced periods. Causes include chronic stress, certain medications (some anti-nausea drugs like domperidone, and several antidepressants and antipsychotics), and occasionally a small benign pituitary growth called a prolactinoma. A tell-tale sign is galactorrhoea — a milky discharge from the nipples when not breastfeeding.

A serum prolactin test costs about ₹350-600. Because prolactin is stress-sensitive, a heavy meal, exercise or breast stimulation shortly before the test can give a falsely high reading, so it is best repeated if borderline. When treatment is needed, dopamine-agonist tablets like cabergoline or bromocriptine usually lower prolactin and restore regular cycles within a few months. Our detailed guide on high prolactin as a cause of missed periods walks through testing and treatment.

The reassuring point is that both thyroid and prolactin disorders are highly treatable, and cycles usually return to normal once the underlying hormone is corrected. If you suspect either, keep a short diary of cycle lengths and symptoms like hair loss, fatigue or nipple discharge — that record helps your doctor move quickly past a "wait and watch" approach.

Both ends of the body-weight spectrum disrupt the brain-ovary signalling that controls your cycle. Being significantly underweight (a BMI under 18.5) can trigger functional hypothalamic amenorrhoea, where the brain senses an energy shortage and switches off the reproductive system to conserve resources. This is increasingly common in young women under intense exam or work pressure, and in those restricting food to lose "wedding weight." Treatment is nutritional rehabilitation; left unaddressed, the low-oestrogen state harms bone density, a real concern given how widespread vitamin D deficiency already is in India.

At the other end, obesity (for Indian/South Asian women, a BMI over about 27.5) creates a different problem. Fat tissue produces oestrogen, and without the progesterone that follows ovulation this "unopposed oestrogen" thickens the uterine lining, causing periods that are infrequent but often very heavy when they come. Over years this raises the risk of endometrial hyperplasia and cancer. A modest, sustainable 5-10% weight loss is usually enough to restore more regular ovulation; checking HbA1c or fasting insulin (about ₹400-800) helps map the metabolic picture.

Very intense exercise can also stop periods if energy intake does not keep up with output — a state known as relative energy deficiency in sport. In India this is seen not only in competitive athletes but in serious classical dancers and women training hard for police or military recruitment. The fix is to rebalance energy by eating more nutrient-dense food (ghee, nuts, seeds) and easing training volume until cycles return. A missing period when you otherwise feel fit is still worth investigating — it is a sign the brain is not sending the ovaries their start signal.

Stress acts through the same pathway. Acute stress can disrupt a cycle or two and usually self-corrects; chronic stress, especially combined with weight loss or heavy exercise, can suppress periods for longer. But "it's just stress" should not become a reason to skip a workup — it often masks a treatable cause like PCOS or thyroid disease. If you want the science, see how long stress can actually delay your period. If a period is absent for more than three months, a pelvic ultrasound and a basic hormone panel (FSH, LH, prolactin, TSH) are the standard next steps, since the irregularity usually reflects that you are not ovulating reliably.

Perimenopause typically begins in the early-to-mid 40s in Indian women — somewhat earlier than European averages — and lasts 4-7 years before the final period. Irregular cycles that become shorter, then longer, then skipped are the hallmark, often alongside hot flushes, night sweats, mood changes, disturbed sleep and vaginal dryness. This is a normal transition that does not need treatment unless symptoms affect quality of life, but it is worth confirming with a gynaecologist to rule out other causes and to discuss bone, heart and breast health. Our guide on perimenopause in Indian women explains what to expect.

Premature ovarian insufficiency (POI), previously called premature menopause, is the loss of ovarian function before age 40 and affects around 1-2% of women under 40. It causes irregular or absent periods, often with hot flushes and other menopausal symptoms, and is diagnosed by a raised FSH (over 25 IU/L) on two separate occasions plus low oestrogen. Causes include genetic conditions, autoimmune ovarian failure, chemotherapy or radiation, and ovarian surgery, though many cases have no identifiable cause. Because POI carries fertility, bone, cardiovascular and emotional implications, it warrants prompt referral to an endocrinologist or reproductive specialist for hormone replacement and a management plan — see primary ovarian insufficiency for the full picture.

Structural problems in the uterus are a major cause of irregular and heavy bleeding. Uterine fibroids — non-cancerous muscle growths — are extremely common and can range from tiny to very large, often causing heavy periods that are wrongly normalised as "just a heavy flow" until iron-deficiency anaemia sets in. If you are changing pads every 1-2 hours or passing clots larger than a ₹2 coin, that points to a structural cause worth investigating. Endometrial polyps, small growths in the lining, more often cause spotting between periods or bleeding after sex. A transvaginal ultrasound gives the clearest view.

Adenomyosis, where lining-type tissue grows into the muscular wall of the uterus, causes a "bulky" uterus with intense, crampy pain that can start days before the period. It is often under-diagnosed because women are expected to endure period pain quietly. Unlike discrete fibroids, it is diffuse and harder to treat conservatively, but a hormonal IUD (Mirena) is now a first-line option that controls bleeding and can avoid surgery — covered in our guide to adenomyosis treatment options. If your periods have become progressively more painful with age, that deserves a proper evaluation rather than just heating pads.

Endometrial hyperplasia — thickening of the uterine lining from excess oestrogen without enough progesterone — is a more serious concern, because untreated atypical hyperplasia can progress to endometrial cancer. It is more likely with PCOS, obesity and in the perimenopausal years. For this reason, persistent heavy irregular bleeding in women over 40, and any bleeding after menopause, warrants an endometrial biopsy (a quick outpatient test) to check the lining. If you have PCOS and have not had a period for more than three months, see a doctor to shed the lining with medication rather than letting it build up. The warning signs of endometrial cancer are important to know.

Infection and scarring also matter in India. Pelvic inflammatory disease and genital tuberculosis can cause irregular cycles and pelvic pain; pelvic TB and vigorous D&C (dilation and curettage) procedures can leave intrauterine adhesions (Asherman's syndrome) that make periods very light or stop them entirely. If you have a history of pelvic surgery, a D&C, or past TB and your periods have become unusually scant or absent, ask about a hysteroscopy to look for scarring, because a past D&C or pelvic TB can leave adhesions that thin or stop your bleeding.

Practical advice: keep a three-month period diary noting pad use and pain; ask for the "endometrial thickness" from your scan report; and if bleeding is heavy, check ferritin (iron stores) alongside haemoglobin, because low iron can itself worsen bleeding. If a hysterectomy is suggested for fibroids or adenomyosis in a woman under 45, it is reasonable to ask about medical management or uterus-sparing options first, and to seek a second opinion if you feel rushed.

Pregnancy is the single most important thing to rule out in any woman of reproductive age with a missed or delayed period, regardless of how unlikely it seems. A home urine pregnancy test (brands like Prega News, i-can) costs ₹50-150 and is over 99% accurate when used correctly. This matters because abnormal bleeding can mimic a period: implantation spotting or an early miscarriage can look like a light or late cycle, and an ectopic pregnancy — implantation outside the uterus — can cause life-threatening internal bleeding while presenting only as spotting and one-sided pain. A pregnancy test should be the entry point for any irregular-bleeding workup.

Hormonal contraceptives are among the most common causes of cycle changes. Combined pills suppress ovulation, and breakthrough bleeding or mid-cycle spotting is common in the first three to six months as the body adjusts. The progestogen injection (DMPA) often stops periods entirely after a few doses, which is medically safe and reversible. India's non-steroidal weekly pill, Saheli (centchroman), works by modifying the lining and can lengthen or unsettle the cycle at first. None of these reflect harm — but it helps to know what your method does.

Non-hormonal and emergency options also affect bleeding. The copper IUD (Cu-T) tends to make periods heavier and crampier in the first months, while a hormonal IUD like Mirena thins the lining and often makes periods very light or absent. Emergency contraceptive pills such as i-Pill or Unwanted-72 work by delaying ovulation, so they can shift the next period earlier or later by several days and are not meant for regular use precisely because they disrupt the cycle.

Other routine medications can interfere too. Some antipsychotics and certain antidepressants raise prolactin and can stop periods; corticosteroids and high-dose painkillers can alter bleeding. Herbal and Ayurvedic supplements taken for "hormonal balance," such as shatavari or ashwagandha, are not automatically side-effect free and can have hormonal effects. Always give your gynaecologist a full list of everything you take, including over-the-counter and home remedies — a medication review is a standard part of the workup.

A practical tip on cost: if long-term medication is needed, ask your doctor for the generic name and buy from a Pradhan Mantri Bhartiya Janaushadhi Kendra, where quality-certified medicines cost far less than branded versions.

In many Indian households the threshold for seeking help is set far higher than it should be — cycles are expected to "settle after marriage" or are mediated by well-meaning relatives. The clinical reality is simpler. Book a consultation if any of the following describe you, and treat the red-flag list below as reasons to be seen promptly rather than to wait.

Public care is affordable: AIIMS and many government hospital OPDs charge ₹10-50, and the Ayushman Bharat (PM-JAY) scheme covers several gynaecological procedures for eligible families. In private practice a specialist consultation typically runs ₹500-2,000. Cost should not be the reason a treatable cause goes unaddressed for years.

Come prepared. Bring a three-month log of cycle start and end dates, pad use on your heaviest day, a pain score out of 10, and any skin, hair or mood changes. Mention all medicines and supplements. If a clinic dismisses your concern as "just part of being a woman," you are entitled to a second opinion.

The workup follows a logical order. First, pregnancy is excluded with a urine or serum beta-hCG test (₹100-400). Next come the endocrine "control" hormones: TSH for thyroid function (₹250-450) and prolactin (₹350-600), because subclinical hypothyroidism and high prolactin are both common and easily missed. Many labs bundle these as an essential hormone panel with a 24-hour turnaround.

If PCOS is suspected, the panel expands. FSH and LH (around ₹600-1,200 together) are ideally drawn on day 2-3 of a natural or induced cycle. Estradiol and AMH (anti-Müllerian hormone) give a picture of ovarian reserve. Because insulin resistance is common in South Asians, fasting glucose, HbA1c and sometimes fasting insulin (₹400-750) are checked. If there are clear signs of androgen excess — stubborn acne, hair thinning, hirsutism — total and free testosterone with DHEA-S (₹1,500-3,500) helps separate PCOS from rarer adrenal causes.

Imaging anchors the workup. A transabdominal ultrasound (₹800-1,500) is usually done first but needs a full bladder; a transvaginal scan (₹1,500-3,500) gives a clearer view of the ovaries and lining for women comfortable with it. If the lining looks abnormally thick or a polyp is suspected, the workup may step up to an endometrial biopsy (₹2,000-4,500) or a day-care hysteroscopy.

A straightforward workup to confirm PCOS in a younger woman may total ₹4,000; a comprehensive panel with AMH and androgens can reach ₹15,000. Corporate health insurance usually covers diagnostics once a doctor has initiated the case, though follow-up lifestyle care and supplements are often out of pocket. Integrated diagnostic packages can reduce individual test prices.

The goal of all this is to turn a vague symptom into a clear plan. Keeping a digital or paper period record gives your clinician the longitudinal data to reach a diagnosis without unnecessary repeat tests. Whether the answer is a lifestyle-led plan for PCOS or thyroid hormone replacement, the workup is the first step in getting your cycle — and the underlying health it reflects — back on track.

Before you see a doctor, the most useful thing you can do is collect data. For at least three to six cycles, record the dates bleeding starts and ends, the number of pads used (more than 12-15 fully soaked pads in a cycle, or roughly over 80 ml, is heavy), and whether you pass clots. An app or a discreet notebook both work. This helps your doctor tell apart infrequent cycles (over 38 days) from frequent ones (under 24 days), which point to different causes.

If you are sexually active, rule out pregnancy first — every government Primary Health Centre provides free test kits through ASHA workers, and chemists stock them for ₹50-150. This matters because some tests for irregular periods, and certain medications, are unsafe in pregnancy. A missed period with a negative test still has a full list of possible causes, from PCOS and thyroid disease to weight and stress.

Diet is a powerful lever, especially given how common insulin resistance is in Indian women. Shifting towards a lower-glycaemic pattern helps: replace polished white rice and maida with millets like ragi, jowar and bajra; build meals around protein such as dal, moong, paneer and curd; and request less oil and added sugar in everyday cooking. A simple plate method — half vegetables, a quarter protein, a quarter complex carbs — is a sustainable, culturally familiar starting point.

Movement and sleep matter too. Aim for about 150 minutes a week of moderate activity plus two short strength sessions — bodyweight squats and lunges at home count. Managing the mental load helps lower cortisol, which interferes with the cycle: even ten minutes of slow breathing (anulom vilom, bhramari) before bed, and a consistent 7-8 hours of sleep, support more regular hormones. Yoga and pranayama are reasonable complements, but they support medical care rather than replace it.

Two cautions. Be wary of "miracle" cycle-regulating powders advertised on social media, and check that your provider is a registered practitioner (MD or DGO). And do not let a slim build reassure you out of getting checked — lean PCOS means you can have irregular periods at a normal weight. If heavy bleeding has left you tired, ask about testing for iron deficiency, which affects more than half of Indian women. These home steps make your eventual clinical visit faster and more useful.

• WHO — Infertility and reproductive health (menstrual disturbances and ovulatory dysfunction)
• ACOG — Abnormal Uterine Bleeding (FAQ and clinical guidance)
• ACOG — Polycystic Ovary Syndrome (PCOS)
• NHS — Irregular periods
• NHS — Stopped or missed periods
• ICMR — National Family Health Survey (NFHS-5) on anaemia in Indian women