What are irregular periods?

Typically, a woman’s menstruation (also called a period) occurs roughly every 28 days — or somewhere between 21 and 35 days. It usually lasts anywhere between four and seven days. For most women, their menstrual flow fluctuates throughout their period, but the pattern is mostly the same from month to month.
However, many women experience irregular periods, which can be unpredictable. For example, an irregular period might mean having a period that occurs more frequently than every 21 days or having a period that occurs less frequently than every 35 days — both of which are outside the normal range for a menstrual cycle.
An irregular period might mean missing multiple periods in a row or missing your period indefinitely. Women with irregular periods also sometimes experience drastic or unpredictable fluctuations in their flow.
Irregular periods often occur with many other symptoms. Side effects of irregular periods might include:
- Heavy bleeding
- Light bleeding
- Intense pain or cramping
- Nausea or vomiting
- Bleeding or spotting between menstruation
- Bleeding or spotting after sex
If you experience irregular periods or any of their side effects, it is important to see your doctor.
Signs of irregular periods
Keeping careful track of your period is an important part of recognizing the signs and symptoms of irregular periods. Many women lose track of the number of days their period usually lasts or when their last menstruation was — making it easy to miss clear signs of an irregular period.
When tracking your menstrual cycle, make sure to make a note of the following details:
When your period begins and ends
Keeping track of when your period begins and ends each month can give you valuable insight into your menstrual cycle. You will be able to track the length of your period, whether or not the length of your menstrual cycle is consistent, and whether you miss any periods.
The amount of flow
It is important to make a note of how much bleeding you experience during your period — both throughout the day and over the week. A typical period follows the same flow pattern most months. Major fluctuations in flow from day to day or throughout the day can signal an underlying medical condition.
It is also important to notice if your period is excessively heavy or light. Dramatically heavy or light periods often occur with other symptoms.
Presence of clots
Pay attention to any clots you pass during your period. Make a note of their size and appearance so that you can discuss them with your doctor.
Spotting
Spotting is a common sign of irregular periods. Spotting is a small amount of bleeding that occurs between menstruation. It may feel like a typical period, but spotting is usually only a few drops or a light flow of blood.
Cramps or pain
Keep a record of any cramps or pain you experience during or near your period. A log of physical discomfort is an important resource when you meet with your doctor.
Headaches or other symptoms
Irregular periods often go hand-in-hand with other uncomfortable symptoms, such as headaches. Keeping track of specific symptoms may help your doctor determine underlying causes.
Any drastic changes in your menstrual cycle
As you keep track of your periods, make a note of any drastic changes. Consult with your doctor if you experience any sudden changes in your period.

QUESTION
What is pelvic inflammatory disease (PID)? See AnswerCauses of irregular periods
There are several potential causes of irregular periods. These include:
Hormonal imbalance
A hormonal imbalance is a common contributor to irregular periods. Hormones help regulate your reproductive system. An excess amount or lack of certain hormones could be disrupting your menstrual cycle, as well as causing heavy bleeding and other symptoms.
Uterine fibroids
Fibroids are benign growths of muscle cells that occur within the uterus. While fibroids are noncancerous, they can affect the size and shape of your uterus and cervix. Depending on where they are developing, how many there are, and how large they have grown, fibroids can have a significant influence on the regularity of your menstrual cycle.
Endometriosis
Endometriosis is a condition in which cells from the uterus grow outside the uterine walls. Endometriosis can cause significant pain and discomfort and affect the consistency of your period.
Stress
Research shows that stress and other risk factors — such as your physical activity level, weight, and age — can have a major impact on your period.
Diagnosing irregular periods
To diagnose irregular periods and determine their underlying cause, your doctor will ask you about your last period and any symptoms you are experiencing. After reviewing your medical history and any record you have kept of your menstrual cycle, your doctor may run additional tests to pinpoint the cause.
These tests might include:
- Blood tests
- Pelvic ultrasounds
- Pap smears
- Pregnancy tests
- Urine collection
Treatments for irregular periods
Because irregular periods can be triggered by a range of underlying causes, there are several treatment options your doctor might recommend. Depending on your symptoms, these treatments might include:
- Hormone therapy
- Hormonal birth control
- Over-the-counter pain relievers
- Surgery
- Exercise
- Stress relief and stress management
- Dietary changes
Research shows that, with treatment or appropriate lifestyle changes, women can often regain regularity of their periods.
Canadian Medical Association Journal: "Irregular menstrual cycles in a young woman."
Cleveland Clinic: "Abnormal Menstruation (Periods.)"
Harvard Health: "When You Visit Your Doctor - Irregular Menstrual Periods."
Journal of Clinical and Diagnostic Research: "To Evaluate the Effect of Perceived Stress on Menstrual Function."
Medicine: "Length of Menstrual Cycle and Risk of Endometriosis: A Meta-Analysis of 11 Case–Control Studies."
Penn Medicine: "Irregular Periods: Why Is My Period Late?"
Top Side Effects of Having Irregular Periods Related Articles
Cramps But No Period
Having cramps but no period can occur because of conditions other than your monthly menstrual cycle. They may feel like period cramps of the lower abdomen when you are not due for your period and produce no blood. These 12 diseases and conditions are examples of what can cause abdominal cramping when not on period.How Can I Stop Prolonged Periods Naturally?
Heavy periods may be a sign of some underlying health condition. Quite often, heavy and prolonged periods may be a result of nutritional deficiencies. There are a few home remedies for a heavy period. Your doctor may use medication or surgery to treat heavy periods.How Late Can a Period Be Before You Know You’re Pregnant?
What is a late or missed period, and what can cause it other than pregnancy? Ovulation occurs between days 12 and 20 of your cycle and you are most likely to get pregnant during this fertile window. Learn the early signs of pregnancy and when to take a pregnancy test to get accurate results.How Can You Tell if You're Pregnant if You Have Irregular Periods?
Learn the signs of pregnancy, what causes irregular periods, and when to see a doctor. One common question that teens and women ask is whether they can become pregnant while on their period.Premenstrual Dysphoric Disorder PMDD Quiz
Premenstrual dysphoric disorder (PMDD) can be serious and debilitating for some women. The good news is that women do not have to suffer. Take this quiz to learn the differences between PMDD symptoms and its milder cousin, premenstrual syndrome (PMS).PMS Slideshow
Premenstrual Syndrome (PMS) can cause from mood swings, munchies, and more. Learn about the symptoms, causes and treatments of PMS.25 Ways to Relieve Menstrual Cramps
Menstrual cramps happen when prostaglandins force the uterus to contract. Dysmenorrhea, or period pain, may be relieved by heating pads, ibuprofen, and other measures. Endometriosis may cause severe cramps during the menstrual cycle. Luckily, women have many options for period pain relief.Spotting vs. Period
Menstruation (a female's "period") occurs due to the shedding of the lining of the uterus. Menstrual bleeding lasts about three to five days, and the bleeding is heavy the first couple of days and then it lessens. Spotting is vaginal bleeding between periods.What Are Signs Your Period Is Coming?
Knowing the signs of a period can help you deal with your menstrual symptoms. Learn how to identify the signs of a period, know when to see a doctor, and find treatment for your period symptoms. Pregnancy is the time when a baby develops in the womb. A period is the time in a woman's monthly cycle in which she bleeds and sheds uterine lining. Early pregnancy symptoms may be confused with period symptoms because they can be similar.What Is the Normal Cycle for Menstruation?
A normal menstrual cycle typically lasts about 28 days long. Check out the center below for more medical references on menstruation, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.Why Am I Getting Brown Discharge Before My Period?
What is brown discharge and why does it sometimes happen before your period? Learn the signs of abnormal vaginal bleeding and what the causes may be.Why Am I Getting Period Cramps With No Blood?
Why are you getting period cramps but no blood? Learn the causes of period cramps without blood and how to treat it. The menstrual cycle is cyclic changes that occur in a woman"s body every month. During the menstrual cycle, the levels of reproductive hormones change, the egg is released from the ovary, and the uterus is prepared for pregnancy.Why Did I Miss My Period on Birth Control?
Missed periods on birth control are a common issue that affects many women. Learn why you missed your period on birth control, how your doctor will diagnose why, and how you can treat your missed period.