Patient education: Absent or irregular periods (The Basics)

What are absent or irregular periods? — 

These are periods that do not happen at all or that happen fewer than 6 to 8 times a year. If you do not get your period for a while, it could be because you are pregnant. Or there might be another reason, such as a medical condition.

What causes absent or irregular periods? — 

They can be caused by:

●Pregnancy

●Polycystic ovary syndrome ("PCOS") – This is the most common cause of irregular periods. In this condition, the ovaries make too much male hormone. This can affect monthly periods and cause excess facial hair, acne, and sometimes problems with weight.

●A decrease in your body's energy supply – This can result from exercising too much, being very stressed, having an eating disorder, or burning more calories than you take in.

●Too much prolactin – This is a hormone made in the "pituitary gland," which is a small organ at the base of the brain.

●Early menopause – Menopause is when you naturally stop having periods. It normally happens between the ages of 45 and 55. But in some people, it happens earlier. "Early menopause" is when people go through menopause between the ages of 40 and 45 years. If menopause happens before age 40, it is called "primary ovarian insufficiency."

●Certain types of hormonal birth control – Some forms of birth control can cause absent or irregular periods. This is expected. It is common to stop having periods if you use the progestin-only pill (sometimes called the "minipill"), the implant, or a hormonal intrauterine device ("IUD").

Changes to your period are also common with birth control pills that have a lower dose of estrogen. Having light or absent periods does not mean that the pill is not working, as long as you take it every day.

If you take birth control pills and use "continuous dosing," you will also not get a monthly period. Continuous dosing means skipping the hormone-free pills that come with your prescription, and taking hormone pills every day instead.

Will I need tests? — 

Maybe. Your doctor or nurse might recommend tests based on your age, other symptoms, and individual situation.

Common tests include:

●Pregnancy test – Pregnancy is a common cause of missed periods. Your doctor will want to find out if you are pregnant before doing any other tests.

●Blood tests – These measure hormones that affect the reproductive system.

●Pelvic ultrasound – This uses sound waves to make pictures of your uterus, cervix, and vagina (figure 1). The pictures can show if there is something wrong with these organs.

●MRI – This uses a large magnet to make detailed pictures of the brain. It can show if there is a problem in the part of the brain that controls the body's hormones. An MRI might be done if blood tests are abnormal.

How are absent and irregular periods treated? — 

That depends on what is causing your missed periods and whether you want to get pregnant. Possible treatments include:

●Birth control pills to make periods regular

●Losing weight, if you have excess body weight

●Medicines to help you get pregnant if you are having trouble getting pregnant on your own

●Changing the way you eat and exercise, such as:

•Eating more calories

•Gaining weight if you weigh too little (calculator 1)

•Exercising less, if you exercise a lot

•Reducing stress

●Hormones to treat hot flashes (if you are going through early menopause or primary ovarian insufficiency)

●Medicines to lower prolactin levels (if your pituitary gland is making too much prolactin)

Can absent and irregular periods be prevented? — 

You can reduce your chances of missing periods by eating well and staying at a healthy weight. Being too thin or too heavy can cause irregular periods.

When should I call the doctor? — 

See your doctor or nurse if:

●You are older than 15 and still have not had your period.

●You used to get periods, but you have not had one for more than 3 months.

●Your periods happen more than 45 days apart.

You should also tell your doctor if you have absent or irregular periods and:

●Think that you might be pregnant

●Have family members with irregular periods

●Have bad acne or hair on your chest or face

●Have gained weight and are having trouble losing it

●Have hot flashes, which feel like a wave of heat that starts in your chest and face and then moves through your body

●Have night sweats, which are hot flashes that happen when sleeping

●Have new headaches or trouble seeing

●Have milky fluid coming out of your breasts

●Are under a lot of stress

●Have recently lost weight

●Are exercising more than you used to

●Have changed how much you eat or what kinds of foods you eat

●Are taking any medicines, herbs, or vitamins

More on this topic

Patient education: Menstruation (The Basics)
Patient education: Polycystic ovary syndrome (The Basics)
Patient education: Primary ovarian insufficiency (The Basics)
Patient education: Prolactinoma (The Basics)
Patient education: Female infertility (The Basics)
Patient education: Sertoli-Leydig cell tumor (The Basics)
Patient education: Pelvic ultrasound (The Basics)

Patient education: Absent or irregular periods (Beyond the Basics)
Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics)
Patient education: High prolactin levels and prolactinomas (Beyond the Basics)