Irregular Periods in Girls (Amenorrhea)

Amenorrhea is when a girl’s menstrual bleeding (period) doesn’t occur. There are two types:

• Primary amenorrhea. This is when the first menstrual bleeding at puberty doesn’t occur by age 15. This problem may be lifelong.
• Secondary amenorrhea. This is when normal menstrual bleeding stops occurring for three months or more. This may be because of a physical cause, and usually happens later in life.

Amenorrhea can have many causes, including:

• Ovulation problems. This can cause irregular or missed menstrual periods.
• Thyroid disorder. In many cases, a thyroid gland that is underactive or overactive can cause missed periods.
• Obesity. Girls who are overweight may have changes in ovulation due to body fat. This can cause missed periods.
• A lot of exercise. Some girl athletes don’t have menstrual periods because of low amounts of body fat.
• Eating disorder. Girls with anorexia or bulimia may have amenorrhea if their body weight is too low.
• Pituitary adenoma. This is a tumor that grows in the brain. It may cause problems with the normal function of hormones. This can prevent ovulation and cause missed periods.
• Physical problem (birth defect). If a girl has not started to menstruate by age 15, it may be from a problem with how the reproductive system formed before birth.
• Pregnancy. Menstrual periods stop during pregnancy.

A teen is more at risk for amenorrhea for any of the below reasons:

• Being an athlete
• Being overweight
• Having an eating disorder
• Having a thyroid disorder
• Having ovulation problems

The main symptom is no menstrual bleeding when it is expected.

The symptoms of amenorrhea can be like other health conditions. Make sure your teen sees her healthcare provider for a diagnosis.

A healthcare provider diagnoses amenorrhea in these cases:

• No menstrual bleeding for three months or more in a girl with previously normal periods
• No menstrual bleeding for six months or more in a girl with irregular periods
• No menstrual bleeding by age 15

The healthcare provider will ask about your teen’s symptoms and health history. He or she will give your teen a physical exam. The physical exam may include a pelvic exam. Your teen may also have tests, such as:

• Blood tests. These look at hormone levels and check for pregnancy.
• Pelvic ultrasound. This painless test uses sound waves to create images of the inside of the body. It can show physical problems of the reproductive system.

The healthcare provider may also need to look for other menstrual disorders, health problems or medicines that may be causing or making the condition worse.

Treatment will depend on your child’s symptoms, age and general health. It will also depend on the cause and how severe the condition is.

Your teen may need to see a gynecologist. This is a doctor who treats the female reproductive system. Treatment for amenorrhea may include:

• Hormone treatment with progesterone
• Hormone treatment with birth control pills (oral contraceptives)
• Medicine to treat thyroid disorder
• Surgery for birth defects or other physical problems
• Changes in diet or exercise
• Treatment of an eating disorder
• Calcium supplements to reduce bone loss (osteoporosis)

Talk with your child’s healthcare provider about the risks, benefits and possible side effects of all treatments.

Possible complications include:

• Thinning bones. If amenorrhea is caused by low estrogen, this can also lead to thinning of bones (osteoporosis) over time. Your teen’s healthcare provider may advise her to take calcium supplements.
• Loss of fertility. If amenorrhea is caused by lack of ovulation, this means pregnancy may be difficult or not possible in the future.

Some preventable causes include eating habits and weight loss or gain. Some of the causes may not be preventable. Talk with your child’s healthcare provider.

Call the healthcare provider if your child has:

• Symptoms that don’t get better, or get worse
• New symptoms