"Line up shortest to tallest!" the teacher calls out. "Not again," some kids might groan — especially if they have to stand at one end or the other.

For most kids, height isn't something they can change, so what do you do if you don't like how tall or short you are? It might be girls feeling too tall and boys feeling too short. But some really tall boys might not like all that height and some shorter girls might get tired of all the jokes or of feeling like they're staying little while their friends are growing up.

It's in Your Genes

But the truth is that everyone is growing up — it's just that they're doing it at their own pace. In other words, your body grows on its own schedule. You can't wish yourself taller or stretch yourself. Or if you're already tall, you can't do anything to hurry your friends up so you're not the tallest one.

For kids concerned about their height, there are two big questions:

1. When will I grow taller (or stop growing)?
2. How tall will I be?

Your genes, which you inherited from your parents, largely determine how tall you will end up being and how fast you'll grow. Kids get taller more quickly during growth spurts, times when their bodies grow fast — as much as 4 inches or more in a year during puberty, for example!

When Does Height Happen?

Your biggest growth spurt happened when you were a baby. In that first year of life, you grew about 10 inches as you got bigger and stronger. Since then, you've probably seen your height increase a few inches a year. You might find out how much you've grown during your annual checkup at the doctor's office or when your pants get too short. Uh, oh — we can see your ankles!

After babyhood, the next big growth spurt for kids comes during puberty, a time of many changes when boys and girls grow bigger and start to look more like adult men and women. But no one can tell you exactly when you'll experience these changes.

Puberty starts at different ages for different kids and it is a process that takes a couple of years. So the getting taller part will happen at different ages, depending on the kid, and whether he or she is a boy or a girl.

In general, puberty starts:

• between ages 8 and 13 in girls
• between 9 and 15 in boys

During puberty, boys and girls will have a growth spurt and grow to their adult height. So that means girls who start puberty the latest will still be getting taller in their mid-teens. For boys, the latest to reach puberty will still be getting taller into their late teens. A few of these boys may grow taller even into their early twenties!

How Tall Will I Be?

You might want to know how tall you will be. Will you be nose to nose with your mom or dad someday? There's no way to know for sure how tall a kid will be as an adult, but it's easy to get a clue: Look at your parents and the other adult members of your family. How tall are they? Chances are you'll be around the same height as your parents. If one parent is tall and one short, then you're likely to end up somewhere in between.

But you could be taller or shorter, too. Boy, there are a lot of "buts" when it comes to height! That's because your height is determined by your genes — the complicated code of instructions that you inherit from your parents. Genes tell your body how to grow and determine lots of things, including how tall you are.

But those genes don't make you an exact copy of your mom or dad. Kids only get some of the genes from each of their parents, and parents don't give the same bunch of their genes to each kid. If you have brothers and sisters, you know this is true. Brothers and sisters can look very different even though you have the same parents. Even identical twins can end up being different heights!

Height-Related Worries

Here are some things some short or tall kids might have to deal with:

You're too short to ride the rides you want to ride at an amusement park.
This one is upsetting. You're all ready to board the super-fast roller coaster and the ride operator says you're too small. Sometimes, you will be allowed to ride with an adult, so try to have one handy.

You still have to use a booster seat in the car.
Though you haven't used a car seat for a long time, older kids are supposed to use a booster seat until they are 4-feet-9-inches tall. The seats are meant to position the seat belt properly in case of a crash. If your friends don't have to use one and you do, you might feel funny about it. On the plus side, sitting higher makes it easier to see and might help if you get carsick and need to keep looking out the window.

You're a girl who's taller than the boys.
This can make a girl feel awkward, especially when it comes time to be paired up, like at a school dance. Eventually, this evens out, but it takes a little while because many girls have their growth spurts before the boys do.

Someone teases you about being too tall or too short.
This kind of teasing is the worst. You can't change your height, so what are you supposed to do? As with most teasing, try not to let it bother you. Tell a teacher, parent, or another adult if it's bothering you and the person won't stop.

What Can I Do Right Now?

If you are still worried about your height, talk to your parents and your doctor. Most kids don't have a growth problem that needs help from a doctor, but it's always OK to ask if you're concerned.

So for most kids, it seems like there's not much to do but wait to see how it all turns out. But you can do something right now: Eat healthy and take care of yourself. If you get the nutrition, sleep, and exercise you need, you're likely to reach your maximum potential height. In other words, you'll grow as tall as you were meant to grow.

And even though you may hear people say it, taking extra vitamins or supplements that you can buy in a store won't help you get taller. Just stick to a healthy diet if you want to be the tallest you can be!

Kids who wish they weren't so tall should still eat healthy and take care of themselves, of course. Eating less won't make you end up any shorter unless you really starved yourself and made yourself sick.

As they get older, most kids learn to feel comfortable with their height, whether they turn out tall, short, or somewhere in between.