Amenorrhea Symptoms & Causes

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What is amenorrhea?

Amenorrhea(pronounced "a-men-or-RE-ah") refers to an absence of menstrual periods. This might mean that your daughter is late in starting them (primary amenorrhea), or that she has started her periods, but stops having them (secondary amenorrhea).

When should my daughter have started her period?
Each girl is different, and there’s no one “normal” age. Most girls will get their periods between the ages of 9 and 15, or about 2-3 years after they start their breast development. If your daughter is very thin or active in sports, this may delay her first period.  If mom was late for her period, then often her daughter follows the same pattern.

When should I be concerned?
Your daughter should be checked out by a doctor such as an adolescent medicine specialist or pediatric gynecologist with expertise in figuring out menstrual problems in teens. So if your daughter hasn’t started her period by age 15 or three years after starting breast development or she has had her period before, but stops having them, or even if she’s just late, it’s always a good idea to check in with a healthcare professional.

How often should my daughter get her period?
Roughly once per month. Most women get their periods about once every 28 days, but anywhere between 21 and 45 days is normal in teens the first 2 years after starting her periods and then 21 to 35 days after that. Some girls are slower getting their periods to regulate than others.

How long should they last?
Periods normally last between 3 and 7 days. They tend to be heavier toward the beginning, but this can vary, too.

For more background on periods, check out the Center for Young Women’s Health’s comprehensive Menstrual Periods page.

What complications is my daughter at risk for?

The most important thing is to figure out the cause of the late periods: 

  • She may be fine and just a little late with regulating her periods. 
  • She may a hormone imbalance called polycystic ovary syndrome and needs to be checked for cholesterol and diabetes.
  • She may have an ovary or thyroid problem and need hormones. 
  • Or she may have low estrogen levels from excessive exercise or low weight, and may be at risk for low bone mass.

Without enough estrogen, not only do menstrual cycles stop, but also the body is prevented from being able to absorb calcium to build strong bones.  This can result in low bone mass. Very little bone mass is added after you are 20 years old, which means that the teen years are very important for getting the right amount of bone for your lifetime.

Everyone (teen girls especially) needs the right balance of exercise, body weight, calcium intake, vitamin D, and estrogen levels to have healthy bones. Make sure that your daughter takes in 1200-1500 mg of calcium and vitamin D (600 units/day).


What causes amenorrhea?

Amenorrhea can have many different causes – that’s why it’s so important that your daughter be checked out by an expert. Some of the causes of primary and secondary amenorrhea overlap, and some are completely different.  Some common causes include:

  • Weight loss or gain and stress are the most common causes of amenorrhea in teens

  • PCOS – polycystic ovary syndrome causes irregular menstrual periods, excess hair growth and acne as well as obesity and easy weight gain in about half of girls with PCOS

  • endocrine problems–There are a number of endocrine problems such as too much or too little thyroid hormone that can cause irregular periods or amenorrhea. High levels of hormones can also be caused by some medications.

  • pregnancy–This is a common cause of amenorrhea in women of all ages. Roughly 800,000 teenagers become pregnant each year.

  • chronic illness–Girls with diseases such as Crohn's disease, cystic fibrosis, sickle disease, lupus, diabetes, celiac disease, and others may have amenorrhea because of low weight or a flare in their illness.

  • ovary problems–An example of this is primary ovarian insufficiency, in which the ovaries do not make enough estrogen to cause periods, often because of a genetic problem or because of treatment with radiation or chemotherapy.

  • congenital anomalies of the reproductive tract–A congenital anomaly of the reproductive tract is a type of birth defect.

  • birth control pills or other contraceptives

  • strenuous exercise (“athletic amenorrhea”): Your daughter has to have a certain percentage of body fat to allow for the hormonal processes that allow menstrual periods. If she’s very athletic, her body fat may be too low. Read more about sports and menstrual periods at the Center for Young Women’s Health.

  • obesity–An excess of fat cells can interfere with ovulation.

  • medication –Encourage your daughter to tell her healthcare provider all of the medications (under- and over-the counter, including medicinal herbs) that she is taking.


What are the symptoms of amenorrhea?

Amenorrhea is defined as a symptom – missing periods. Depending on what’s causing your daughter’s amenorrhea, she may have other symptoms too, including excess hair growth, acne, headaches, and pain. :


Q: Is it really a big deal to miss a couple of periods?
It can be, so it’s important to get it checked out and find out what is causing the problem.

Q: When will my daughter’s periods come back?
A: If she had periods before, it is very likely that once the cause is found she will either get periods on her own or can take medicines to help her get periods. 

Q: Will my daughter have a pelvic exam?
Many girls don’t need to have pelvic exams–sometimes a general physical exam, ultrasound, and blood tests are all that is required. But no matter what, our doctors have lots of experience providing expert,  care to girls of all ages.

Q: What’s causing my child’s amenorrhea?

A: Your child’s health care professional will be able to give you a diagnosis for your child’s amenorrhea. There are lots of causes of amenorrhea and with a careful evaluation we will be able to explain what is causing the problem..

Q: Is there anything my daughter should be doing?
A: Encourage your daughter to eat healthful meals, with plenty of calcium and vitamin D, and engage in healthy exercise, maintaining a healthy weight. These are all things that will serve your daughter’s body well now and into the future.

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