During the three to five years that it takes for a girl to get through puberty, there’s a LOT of stuff going on. Some of the changes can be exciting, but many create anxiety. Girls worry most about whether their body is changing in a normal way. They worry if they are first to develop; they worry if they are developing later than all of their friends. And when bodies are changing and doing new things that they don’t understand, they worry that something is wrong.

When girls understand what’s normal and expected, they face the changes with greater confidence and less anxiety. After two decades of leading girls’ puberty eduction programs and receiving thousands of questions through our website, we know what girls (and their moms) worry about the most. Below, we present five things that your daughter needs to know about puberty before it happens (so she won’t worry!).

Breast buds are not cancer.

The first sign of breast development is a firm knot under the areola, called a breast bud. Often, one side “buds” first, then the other bud shows up weeks or months later. Breast cancer awareness has made such great strides that even little girls know that lumps in the breast are concerning. Many young girls have had family members with breast cancer, and they worry that their own breast bud is also cancer. Girls (and moms) need to understand that the tender knots that happen under the areola between the ages of 7 and 12 are not cancer, but are caused by normal breast development and will disappear in time. For help with breast concerns, go HERE.

Vaginal discharge is normal.

Women don’t typically talk about vaginal discharge during every day conversations, so many girls have never heard of it. When girls start to notice a new wetness or “crust” in their underwear, many have no idea what it is or if it’s normal. There are a few things that they need to know about discharge: it begins soon after breasts begin to develop; it is the way the vagina cleans itself; and it’s something that all girls and women have (even though they don’t usually talk about it!). In early puberty, vaginal discharge can be irritating to the sensitive vulvar skin (until the hair fills in and helps keep the discharge off of the skin), so knowing how to manage it is helpful, too (we cover that in our Puberty class available to subscribers).

Nobody can tell you’re on your period unless you tell them.

Do you remember thinking that people could see your bulky pad through your clothes? Did you ever believe that others could tell you were having your period by the way you looked, smelled or acted? Girls today still worry about these things, but they’re simply not true. Young girls want reassurance that others cannot tell when they are having their period. As they mature and get used to menstruation, however, we hope that they will have the confidence to not care if others know they are having a period, because periods are NORMAL! Make sure she’s prepared and confident with this class.

Emotions come from experiences, not hormones.

Adults may need this lesson more than girls, but everyone should understand that emotions are not caused by hormones. Emotions are reactions to things that people experience and feel. Sure, hormonal changes can make emotional reactions bigger, but as girls enter puberty, help them get in the habit of naming their emotions and identifying what triggers them. This is a valuable skill that will help them throughout adolescence and into adulthood. Girls (and boys) are especially empowered when they find healthy ways to identify, express, and manage their emotions, especially the more difficult ones like sadness, anger, jealously or disappointment.

Your body is amazing.

With all the body shaming and unrealistic body images that dominate the media and our culture, too many girls grow up believing they are not pretty enough, thin enough or fit enough. As puberty brings on changes in body size and shape, girls need to practice trusting and caring for their body. They need to know it is amazing because of the things it can do. Help girls value their body for what it helps them accomplish. Help them normalize NORMAL and recognize that the “ideal” created by the media and fashion industry is mostly unattainable and often unhealthy. Finally, be someone who models respect for body diversity and values others for their actions and deeds over appearances. Our video class How to Like Your Body was created to help girls develop this mindset and the practices that prevent body dislike.

 

 

 

One afternoon when I was driving carpool, my daughter’s friend was telling us about how much she enjoys running cross country. She listed several things that make it her favorite sport—being outside in nature, running with friends, getting exercise—but one of those things was “and I don’t have my period during cross country season. It’s great!“

To which the other three girls in the car reacted with jealous comments that they might join cross country for that!

As an ob-gyn, I wanted nothing more than a giant red flag to wave around that car. I knew I had to chat with her mom and the cross country coach—and ultimately the entire team—about something called RED-S.

Here’s why.

Her Period Is Actually a Vital Sign

I get it. Periods can be inconvenient, messy, and sometimes uncomfortable. But it’s really important to understand that having a regular menstrual cycle is actually one of the best indicators that her body has enough energy to do all the amazing things it needs to do—including building strong bones, maintaining a strong immune system, and yes, performing well in sports.

When her period stops or becomes irregular during intense training, it’s not a perk. It’s her body waving a red flag that says, “Hey! I don’t have enough fuel to keep everything running!“

What Is RED-S?

RED-S stands for Relative Energy Deficiency in Sport. It’s what happens when athletes don’t eat enough calories to support both their training AND all the other things their bodies need energy for—like growing, thinking, healing, and having periods.

Think of it this way: The body is like a phone. If it’s constantly being used all day but only charged to 20%, eventually it’s going to shut down some functions to conserve battery. The body does the same thing when it doesn’t get enough “charge” (fuel in the form of calories). It starts shutting down things it considers “non-essential”—and unfortunately, the reproductive system is one of the first to be affected.

The Three Big Problems

When we first started recognizing this pattern in female athletes, we called it the “Female Athlete Triad” because it involved three interconnected problems:

1. Not eating enough for activity level – Sometimes this is intentional (trying to stay lean for a sport), and sometimes it’s unintentional (just not realizing how much fuel she actually needs). Most active teen girls need at least 2,000-2,400 calories per day, and athletes need even more. 
2. Missing or irregular periods – When the body doesn’t have enough energy, it saves energy by shutting down the hormones that control the menstrual cycle. 
3. Weak bones – Those same hormones (especially estrogen) are also what help build strong bones. When estrogen levels are low and periods stop, girls are not building bone density during the exact years when they’re supposed to be. This means stress fractures now and possibly osteoporosis as early as young adulthood. 

The Red Flags

How do you know if your daughter or someone you care about might have RED-S? Look for these warning signs:

• Missing periods or very irregular cycles
• Frequent injuries, especially stress fractures
• Always feeling tired or run-down
• Performance getting worse instead of better
• Getting sick a lot
• Overly focused on food, weight, or body composition

What to Do About It

The good news? RED-S is treatable. The main goal is to restore energy balance:

Increase calories. She might need to add 300-600 calories per day, with a focus on protein and carbohydrates. Working with a sports nutritionist is really helpful.

Possibly reduce training. Sometimes athletes need to dial back training by 10-20% temporarily to let the body recover.

Build bone health. Ensure she’s getting enough calcium (1,200 mg daily) and vitamin D (1,280-2,000 IU daily) through food and supplements.

Get her period back naturally. Once energy balance is restored, her period should return on its own within a few months. That’s how you know she’s getting better. (And no, birth control pills don’t fix this—they just mask the problem.)

Work with a team. The best treatment involves her doctor, a sports nutritionist, possibly a mental health counselor, her coach, and you—all working together.

Back to That Carpool Conversation

After that carpool ride, I did reach out to my daughter’s friend’s mom. We had a good conversation, and together we connected with the coach. The result? The whole cross country team got education about RED-S, several girls got evaluated by their doctors, and the team culture shifted to emphasize healthy fueling.

That runner? She’s doing great now, with regular periods and no stress fractures. And she still loves cross country—maybe even more, because now she has the energy to truly enjoy it.

If your daughter is an athlete who’s missing periods, please don’t brush it off. Her period isn’t just an inconvenience—it’s a vital sign. And when it goes missing, her body is trying to tell you something important.

Listen to it. Her future self will thank you.

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