Everyone knows that kids and teens have growth spurts on the way to adulthood, but in fact, they often have more of them than most people realize. Growth spurts in teens can be both frightening and exciting to them, but they are a natural part of everyone’s life.

In this article, we’ll discuss some basic facts about growth spurts so that if you have a teenager, both of you will know what to expect.

What Are Growth Spurts?

Growth spurts and milestones are two different things. Milestones happen at a normal pace, whereas growth spurts involve kids experiencing a lot of changes in height and weight in a very short period of time. They are similar to growing pains because sometimes they occur so fast that the body can actually experience soreness.

While all teens experience growth spurts, the age at which the spurts occur are a little different for boys and girls. Girls tend to hit a growth spurt between the ages of nine and 15, whereas boys’ growth spurts happen between the ages of 12 and 17.

Even more interesting is the fact that the average teenager will grow three to four inches during just one growth spurt, and these spurts can cause changes in the teens’ eating or sleeping habits, not to mention their emotions.

What Happens During Growth Spurts?

During puberty, growth spurts speed up the physical characteristics that make up both boys and girls. For girls, these include changes such as:

• Puberty begins: 8–13 years of age
• First change to occur: development of breasts
• Pubic hair development: shortly after the development of breasts
• Growth of underarm hair: approximately 12 years of age
• Menstrual periods: usually between the ages of 10 and 16.5

For boys, changes during puberty include:

• Puberty begins: 9.5–14 years of age
• First change to occur: enlargement of testicles
• Enlargement of penis: roughly one year after testicles enlarge
• Pubic hair development: around 13.5 years of age
• Voice change, hair on arms and face: roughly 15 years of age
• Nocturnal emissions (“wet” dreams): around 14 years of age

Keep in mind that these are just average numbers, so there’s likely no need for alarm if your teen gets to these milestones at different times than those mentioned here. As far as emotional and developmental changes, here are some that affect both boys and girls during their teen years:

• They can set specific goals
• They can think long-term
• They can think abstractly
• They can compare themselves to their peers
• They can become concerned about social issues, politics, and other matters

Is It Possible to Have a Second Growth Spurt During Puberty?

Yes, it is entirely possible for more than one growth spurt to occur during puberty. In fact, many times, a growth spurt is followed by a short period of slow growth and then another growth spurt, which can be difficult both physically and emotionally for a lot of teenagers.

The thing is that growth spurts do not start in puberty. In fact, growth spurts usually occur throughout childhood and into early adulthood for most people. Babies, for example, usually double their height by the age of five and triple their weight by the age of one.

Many people, in particular boys, can even experience another growth spurt in their late teens or even their early twenties. This doesn’t happen to everyone and is less common in girls, but it is still a possibility for everyone.

Is One’s Height Mainly Genetic?

For the most part, people’s genetic makeup is what’s responsible for their height being what it is. As a general rule, 60–80% of a person’s height is determined by genetics. Other factors, most noticeably environmental factors such as proper nutrition, can affect the other 20–40%.

There are more than 700 variants in people’s genetic makeup that contribute to their height. The contributions those variants make are individually small, but the combination of the variants is what results in how tall (or short) a person is.

In fact, a lot of these genes directly affect the cartilage in an individual’s growth plates, and it’s these plates that are responsible for lengthening kids’ bones as they grow. Siblings, however, can end up at different heights because the effect of their genes can be different from one sibling to another.

That being said, most kids do end up at around the same height as their parents once they reach adulthood, and sometimes they’ll be even a little taller. Each generation does seem to get a little taller and bigger than the previous generation due to many genetic and environmental factors.

Is It Normal That I’m 21 Years Old and Still Growing Taller?

Most scientists and specialists do not like to use the term “normal” because every person is different. The truth is that by the age of 20, and often sooner, most people are as tall as they’re going to get. Some people, however, will continue to grow past the age of 20, although this is not that common.

If you are past the age of 20 or 21 and still growing, it’s likely no cause for concern. Although it’s rare for both men and women to grow taller once they become adults, it does happen. Nevertheless, if you are already an adult and your height seems to be growing quite a bit, it’s not a bad idea to share this information with your doctor.

One of the reasons most people stop growing by adulthood is because of the aforementioned growth plates. In most individuals, the plates will likely harden, aka “close,” by the age of 16 in girls and 14–19 in boys. Once this happens, growth no longer occurs.

Another reason for this phenomenon is the fact that hormonal changes, which affect both growth plates and other characteristics, stop once people reach adulthood. If you’re 20–21 years old and still getting taller, it shouldn’t be a concern unless there is a lot of growth happening. Small changes are usually not a concern.

Does Body Hair Have Anything to Do with Height?

In a way, body hair does have something to do with height, but the two characteristics are not directly related. Hair growth is affected by hormones, and as long as hormones are in the right amounts, both boys and girls will continue to grow taller.

Nevertheless, after puberty, both genders, but especially boys, can continue to have a lot of body hair, but that doesn’t mean they’re still growing. In addition, body hair can continue to increase even after puberty is over and done with, with some individuals continuing to get more body hair until their early twenties.

For most people, by the time they reach their early- to mid-20s, body hair remains the same because hormones are already there and are at the perfect levels. Essentially, people’s body hair and height can continue to grow at different rates, affected mostly by their hormone development.

Conclusion

Growth spurts can occur several times during puberty, just as they can during infancy, childhood, and occasionally even into early adulthood. However, different individuals can hit certain milestones at different times, so if your teenager isn’t experiencing the milestones like their friends are, there’s usually no need to worry.

The important thing to remember is that if you have any concerns about your child’s development, you should feel free to consult with their pediatrician.