Puberty and menstruation can start as early as age 8 or 9 for some girls. However, most girls in the United States get their first period when they are around 12 or 13 years old. Only a small percentage of girls start menstruating before age 10.
What is the average age for a girl to get her first period?
The average age for a girl to get her first period (menarche) in the United States is between 11 and 12 years old. However, it’s normal for puberty and menstruation to start anytime between ages 8 and 15. Here’s a breakdown of when girls typically get their first period:
- By age 12: 10% of girls
- By age 11: 25% of girls
- By age 13: 90% of girls
- By age 15: 98% of girls
As you can see, less than 10% of girls start their periods before age 11. Only about 2% of girls in the U.S. start menstruating before age 10.
What factors influence when a girl gets her first period?
There are several factors that determine when a girl will get her first period:
- Genetics: Girls often start puberty and get their periods around the same age as their mother and other female family members.
- Body weight: Girls who have a higher body mass index (BMI) and more body fat tend to start puberty earlier.
- Diet: A diet high in animal proteins, soy, and phytoestrogens may promote earlier puberty.
- Environmental factors: Chemicals, hormones, and pollutants in the environment may contribute to earlier puberty in some cases.
- Geographic location: Girls who live closer to the equator or at lower latitudes tend to start puberty up to a year earlier.
- Health conditions: Certain disorders or chronic illnesses can influence puberty timing.
Is it normal to get your period before age 10?
While most girls in the U.S. get their first period between ages 11-13, it is still considered normal to start menstruating a little earlier, between ages 8-10. Here’s an overview:
- By age 9: Less than 1% of girls
- By age 10: 1-5% of girls
- By age 11: 10-25% of girls
So while it is still in the normal range, only about 1-5% of 10 year old girls will have started menstruating. If your daughter gets her first period before age 8, it would be considered precocious puberty and you should talk to her doctor.
Reasons a 10 year old may start her period
There are a few reasons why a small percentage of girls may start puberty and get their first period at age 10:
- Genetics – if female family members also started menstruation early.
- Being overweight – extra body fat can lead to earlier puberty.
- Consuming a diet high in animal proteins.
- Environmental hormone disruptors or other exposures.
- Having certain medical conditions like congenital adrenal hyperplasia.
- Unknown factors that cause her biological clock to start early.
While the specific trigger may not be identified, starting puberty before age 8-10 is still considered normal for a small percentage of girls. But if it happens, a girl should see her pediatrician to rule out any underlying issues.
Physical development of 10 year old girls
In addition to menstruation, 10 year old girls may show other signs of physical development and puberty changes:
- Breast growth: The first signs of breast buds may emerge.
- Pubic and underarm hair: Coarse, darker hair may start growing.
- Body growth: Rapid height growth is common.
- Body shape changes: Hips may start widening.
- Oily skin: Hormonal changes can make skin oilier.
- Body odor: Perspiration and bacteria can cause more odor.
Keep in mind that it’s also perfectly normal for a 10 year old girl to show no signs of puberty or physical maturation. Every child goes through puberty at her own pace based on her biological clock.
Emotional changes in 10 year old girls
Starting menstruation is one of the biggest indicators that a girl has begun puberty. She will also start experiencing emotional changes related to puberty hormones:
- Mood swings
- Anxiety or depression
- Self-consciousness about her changing body
- Withdrawing from family and becoming more private
- Interest and crushes on boys
Keep an open line of communication with your 10 year old daughter and let her know that it’s normal to feel up and down as her body changes. Be understanding but set reasonable limits on behavior.
Is there any concern if a 10 year old gets her period?
While the timing is on the early end of normal, there is likely no reason for concern if your 10 year old daughter gets her first period. However, you should still mention it to her doctor to rule out any possibility of precocious puberty or an underlying condition. Reasons to see the doctor include:
- Periods start before age 8
- Signs of puberty start before age 6-8
- Puberty signs progress very rapidly
- Possible hormone or growth problems run in the family
Early puberty can impact a girl’s emotional development and even her final adult height. So it’s important for a pediatrician to monitor growth and development.
Health impacts of early menstruation
Some research shows that girls who get their periods at younger ages may face some health risks later in life. Starting menstruation before age 12 is linked to:
- Higher risk of breast cancer
- Increased risk of heart disease
- Higher rates of depression during adolescence
- More likely to engage in risky behaviors as a teen
However, keep in mind that many girls start their periods normally between ages 8-11 with no negative health impacts. Talk to your daughter’s doctor if you have any concerns.
Tips for discussing first periods with a 10 year old
Here are some tips for having an open, positive talk about getting her first period if your 10 year old daughter is showing signs of puberty:
- Explain what a period is and what it means for her body.
- Make sure she understands it’s normal, like going through any other change.
- Give an overview of how to use pads/tampons to manage periods.
- Talk about the emotional changes she may experience.
- Emphasize that she can come to you with any questions or concerns.
- Consider giving her a puberty book for pre-teen girls.
Continue the dialogue over time so she knows she has your support through this new phase of life. Being open and positive can help her have a healthy attitude about this milestone.
Conclusion
Only a small percentage of girls in the U.S., around 1-5%, will start menstruating as early as age 10. While not as common as getting a first period at ages 11-12, some girls will normally develop early. If your daughter is among the few who start puberty before age 10, the key is monitoring her development and ensuring there are no underlying issues. With support from family and her health provider, early menstruation can be managed for a healthy transition through this puberty change.