Irregular Periods in Teens and Pre-Teens

As a young teen or pre-teen, irregular periods are normal. If a girl is otherwise free of health problems, there’s no cause for concern. Many factors can affect menstruation, including the onset of puberty, growth spurts, and others.

For example, some girls experience what’s called dysfunctional uterine bleeding (DUB). This typically is caused by the ovaries failing to release an egg. As a result, a girl’s period may be earlier or later than expected. It may also be heavier than usual. 

Girls often experience DUB because their menstrual cycles haven’t established a rhythm yet, and they aren’t ovulating.  

Common Menstrual Irregularities

Most girls get their first period between the ages of 10 and 15, though some start menstruating before or after that age range. After a girl has her first period, it can take up to two years for a consistent, regular cycle to develop.

It’s not at all unusual for a girl’s periods to be inconsistent initially. Menstruation can vary in a variety of ways, including: 

• Oligomenorrhea. This involves having menstrual periods more than 35 days apart. 
• Menorrhagia. This term refers to heavy menstrual periods.
• Amenorrhea. This condition is the absence of a menstrual period. 
• Dysmenorrhea. This term means painful menstrual periods.
• Prolonged periods. Bleeding that exceeds eight days is considered prolonged.

It’s understandable for a girl to be confused by irregular periods, and she should be encouraged to talk freely about her situation with her parents, doctor, or trusted friends. 

What Causes Irregular Periods in Teens and Pre-Teens?

In addition to the variations that are a normal part of the body establishing its menstrual cycle, other factors can affect the frequency and volume of a girl’s periods, including:

• Excessive exercise
• Very high or very low body weight
• Thyroid disorders
• Certain medications
• Hormone imbalances, including polycystic ovary syndrome (PCOS)
• Not consuming enough calories

Tips for Coping with Irregular Periods

Irregular periods tend to even out and become more consistent with time. Still, it can be stressful for pre-teens and teens not to know when their period will start. 

Girls or their parents will sometimes ask about how to cure irregular periods in teenagers. The reality is it’s more about understanding and managing menstrual irregularities.

Here are some things that can help a girl cope:

• Learn the signs that their period will start soon. This can include cramping, spotting, bloating, tender or swollen breasts, mood changes, and acne.
• Keep period products readily available. Girls should have tampons or pads where they can get to them as needed at home, school, etc.
• Try menstrual underwear. These garments can be helpful for girls who aren’t sure when their period will start. 
• Talk with women about their experiences. Most women have stories about the first few years after getting their first period. Hearing how they made it through what can be confusing and frustrating times can be very reassuring. 

When to See a Doctor About Irregular Periods

There are times when irregular periods can indicate a medical problem. Girls and their parents should get advice from a physician about symptoms like:

• Periods that were regular but now are not
• Periods that last more than a week
• Spotting between periods
• Especially heavy periods
• Periods with severe abdominal pain or cramping
• The sudden absence of periods
• Periods that occur more than every 21 days
• Periods that occur less than every 45 days

Learn More About Women’s Health from Baptist Health

Our women’s services team is happy to answer any questions girls or parents have about irregular periods or other aspects of women’s health. Learn more.