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Irregular Periods in Teen Girls: What’s  Normal Menstruation for Teen Girls?

Is it normal to skip periods or have heavy or irregular periods as a teen? Different things can cause irregular mensuration in teens like weight loss, stress, and PCOS.
Irregular Periods in Teen Girls
Updated: September 8, 2023
Medically reviewed by  Shari Nethersole, M.D.

While it is common for girls to have irregular periods during the first year they start menstruating, it's not normal to go several months without a period after having them regularly for many months. 

The medical term for not having periods is amenorrhea, and when this condition goes beyond about three months, further evaluation is usually needed.

According to Dr. Shari Nethersole, a Boston Children's Hospital physician, it’s possible no underlying abnormality is present and that your daughter will start to have menstrual cycles again within another month. However, various hormonal problems can cause menstrual cycles to stop in teenagers. 

The good news is that most of these problems are quite treatable, but diagnosing and treating them early is best.

As someone who has struggled with irregular, heavy, and often painful periods most of my life, I understand well the stress and discomfort this condition can bring.

Related: Should I Throw My Teen Daughter a Period Party?

Is Skipping Periods Normal for Teens?

Is Skipping Periods Normal for Teens?

Because menstrual cycles are a topic your child may feel uncomfortable discussing with you, it is important to open the lines of communication early, long before they begin to have their first period. The more open and honest you are with your child, always at an age-appropriate level, the more comfortable they will be to talk to you when things don’t feel right. 

You can gift your daughter one of many excellent and informative books to help her understand what is going on with her body if she’s reluctant to talk to you.

It is recommended that a female begin seeing a gynecologist around 11, at the onset of her period, or if there are concerns of delayed menstruation or delayed menarche (periods). Their pediatrician can address most general concerns, but your daughter may feel more comfortable speaking to a gynecologist.

What Age Should I Expect My Daughter's Period to Begin?

What Age Should I Expect My Daughter’s Period to Begin?

Most girls begin menstruating between 12 and 14. Some girls may have menstrual bleeding as early as 10 or 11, and others as late as 15 or 16. 98% of girls have their first period by 15; if your daughter has not experienced a cycle by 15, it is time to call a healthcare provider. The term primary amenorrhea applies to a girl who has not experienced her first period by age 15.

Parents should also consider their family history; if mom was late, chances are your family are simply late bloomers. Other factors to consider are whether or not your daughter’s breasts have developed and if she’s experienced any vaginal discharge yet. 

Hormone levels begin fluctuating long before regular periods begin. Breasts typically develop 2-3 years before periods begin, and vaginal discharge occurs 6-12 months prior. 

Why Do Teens Stop Having Periods?

Why Do Teens Stop Having Periods?

One of the common reasons that a girl stops having her menstrual periods for many months is weight loss. Amenorrhea often occurs when a girl's body fat level goes below 12 to 15 percent. 

Too much exercise can contribute to menstrual irregularities. Girls who are athletes -- particularly runners, gymnasts, and dancers -- are more prone to this as they intensify their training. It's also a common consequence in girls who have eating disorders.

Weight gain or obesity is another cause of delayed menstruation in young girls. This is because the body needs normal fat levels to signal puberty. 

Other causes of irregular periods are stress, medication, genetic or physical problems, or other underlying health issues. 

If the body is experiencing extreme amounts of stress, it can pause or delay menstruation. Adolescent girls and young women face unprecedented amounts of stress, from schooling to athletics, to family problems, or cyberbullying

Medications for depression, cancer, allergies, and high blood pressure may affect the menstrual cycle.

In rare instances, a problem with the shape or functioning of the vagina, ovaries, fallopian tubes, or uterus can lead to menstrual disorders.

Medical conditions may lead to dysfunction in the menstrual cycle. Conditions related to the thyroid, pituitary gland, and hypothalamus, which all control hormones and could cause hormone imbalances, may be the culprit. A common cause in women is polycystic ovary syndrome or PCOS. In addition, rare genetic conditions like fragile X syndrome, Turner syndrome, and androgen insensitivity syndrome may also cause irregular cycles.

Lastly, pregnancy may be the reason your daughter is no longer menstruating. While the idea of your daughter being sexually active and becoming pregnant is enough to make most parents want to hide under a rock, you shouldn’t dismiss it.

Talk with your teen about safe sex and consider allowing her to use birth control if there’s even the slightest chance she may be sexually active. Using oral contraceptives also protects your daughter from an unwanted pregnancy in the rare and horrible instances of rape or sexual abuse.

When Should I Call the Doctor About Irregular Periods?

When Should I Call the Doctor About Irregular Periods?

Sometimes as parents, we rush to call the doctor for every little concern only to discover that we may have overreacted. However, Dr. Nethersole recommends you make an appointment at your daughter’s gynecology office as soon as you notice an issue.

The hormones that are present during the menstrual cycle are essential in helping to increase and maintain bone density in teenage girls. Girls who have prolonged periods of amenorrhea will lose some bone density and thus have an increased susceptibility to fractures now and a greater susceptibility to osteoporosis and fractures later on in life.

Calling the doctor is also wise if your daughter is experiencing abnormal hair growth, finds it painful to insert a tampon, or has intense or debilitating cramping. 

Very Heavy Periods May Require Seeing a Doctor

Your daughter should also see the doctor if she’s experiencing heavy periods with substantial blood loss or unexplained uterine bleeding, which could lead to anemia. Menorrhagia is a serious condition that requires medical attention. 

Menorrhagia is characterized by seven days of heavy uterine bleeding with severe cramping. Fatigue, passing blood clots, needing more than one pad or tampon per hour, or shortness of breath are also symptoms. 

Treatment for Irregular Periods

The first step in treating your daughter’s irregular period is discovering the cause. Some girls may have irregular menses because they are still developing. If this is the case, doctors recommend a wait-and-see approach. 

A girl experiencing particularly heavy or painful cycles may benefit from taking birth control pills. Birth control gives a girl more control over her life and alleviates many nasty symptoms associated with heavy periods. 

PCOS in Teens: Signs and Treatment Options

PCOS in Teens

If your daughter is diagnosed with PCOS or another medical condition, their physician will make the best treatment decision based on their age, symptoms, and medical history.

PCOS is very common in women between the ages of 20-40; however, girls as young as 11 have been diagnosed. PCOS is characterized by small ovarian cysts on one or both ovaries. The cysts are not tumors and not cancerous. 

PCOS is caused when a female produces too much of the male hormone androgen and not enough female hormones. Symptoms of PCOS include excess facial hair growth, weight gain, acne, head hair loss, pelvic pain, and depression. 

PCOS cannot be cured but can be treated and controlled through diet, exercise, hormonal balancing, weight loss, and topical medications for acne and hair loss.

Many potential causes and underlying issues may be causing your daughter’s irregular, delayed, or heavy menstrual periods. Rarely are these conditions serious but left untreated, they can significantly impact your daughter’s overall health and quality of life.

Most conditions are easily treatable via birth control, changes to diet and exercise, and other lifestyle adaptations. The best course of action is to contact your pediatrician or gynecologist as soon as you notice a pattern of abnormal symptoms so you can get your daughter back to feeling like herself!

L. Elizabeth Forry

About L. Elizabeth Forry

L. Elizabeth Forry is an Early Childhood Educator with 15 years of classroom… Read more

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