--- title: "Missed period: When to See a GP | HealthAnswers" description: "A missed period is most often caused by pregnancy, stress, weight change, PCOS or thyroid disease — see a GP after three missed periods in a row." url: https://healthanswers.co.uk/symptoms/missed-period/ robots: noindex --- # Missed period: When to See a GP | HealthAnswers Symptoms A missed period is most often caused by pregnancy, stress, weight change, PCOS or thyroid disease — see a GP after three missed periods in a row. Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 3 July 2026 ## Quick answer What could missed period mean? A missed period is often caused by pregnancy, stress, significant weight change, polycystic ovary syndrome (PCOS) or thyroid disease. Take a pregnancy test first if you are sexually active, as pregnancy is the most common cause. See a GP if you have missed three periods in a row, which is known as amenorrhoea. ## Who is this page for? This page is for people in the UK who want a plain-English overview of Missed period, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally. ## Who should skip this page? Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland. On this page 4 sections ## Common causes of missed period - Pregnancy is the most common cause of a missed period in people who are sexually active. - Stress and significant weight loss can disrupt the menstrual cycle. - Polycystic ovary syndrome (PCOS) is a common cause of irregular periods. - Thyroid disease can affect menstruation and cause missed periods. - An absence of periods for three months is known as amenorrhoea. ## Understanding a missed period A single missed period is common and is often nothing to worry about. A prolonged absence of periods, however, needs investigation to find the cause. ## Common causes of a missed period Pregnancy, polycystic ovary syndrome (PCOS), thyroid disease and stress are among the most common causes of a missed period. Contraception can also alter your bleeding pattern, so a missed bleed while using contraception is not always significant. ## What to do about a missed period Take a pregnancy test first if there is any chance you could be pregnant. It also helps to track your cycles, because a record of your periods gives your GP useful information if you need an assessment. ## When to see a GP about missed periods See a GP if your periods have been absent for three months, which is known as amenorrhoea, or if you have concerns about your fertility. Your GP may arrange blood tests and an ultrasound scan as needed to find the cause. ## ! When to get medical help for missed period See a GP if you have missed three periods in a row, or if irregular cycles are worrying you. Call **111** for urgent advice when you are unsure what to do. ## Common questions about missed period How late can a period be and still be normal? A period that is up to a week late can be entirely normal. If there is any chance you could be pregnant, take a pregnancy test to rule this out. Can stress stop your periods? Yes, significant stress can disrupt ovulation and stop your periods. A major change in weight can have the same effect on the menstrual cycle. What is PCOS and how is it diagnosed? Polycystic ovary syndrome (PCOS) is a condition that causes irregular periods, acne and excess hair growth. It is diagnosed using blood tests and an ultrasound scan. Is it normal to have no bleed while on the pill? Yes, having no bleed is often normal on continuous or low-dose pills. Mention it at your contraception reviews so it can be checked if needed. ## Sources - [NHS — Periods And Fertility](https://www.nhs.uk/conditions/periods-and-fertility) - [NHS — Polycystic Ovary Syndrome](https://www.nhs.uk/conditions/polycystic-ovary-syndrome)