Puberty is a key stage in the transition from childhood to adulthood. It is a normal part of growing up, and each person’s experience of it is unique.
Puberty can be a challenging and confusing time. Knowing what to expect and why these changes happen can help a person feel more in control as they go through it.
This stage of life involves many physical and psychological changes, which result from shifts in hormone levels.
Puberty usually begins between the ages of 8 and 14. It tends to happen in females earlier than in males.
This article gives an overview of puberty, including what changes to expect, when they happen, and why.
What is puberty?
During puberty, the body goes through many internal and external changes. Among other things, this is the time when a person:
- reaches their adult height and body proportions
- develops external sex characteristics
- becomes able to reproduce
The physical and psychological changes of puberty happen slowly over time. They typically begin between the ages of 8–13 in females and 9–14 in males.
Puberty lasts throughout the teenage years. A person may be 20 years old by the time all the changes take place.
What happens during puberty?
Puberty begins when an area of the brain called the hypothalamus starts signaling to the rest of the body that it is time to develop adult characteristics.
It sends these signals through hormones, which cause reproductive organs — the ovaries in females and the testes in males — to produce a range of other hormones.
These hormones cause growth and changes in various parts of the body, including the:
- external reproductive organs
- breast tissue
The skin becomes oily and the body produces more sweat. Many people develop some form of acne. Some people start using deodorant.
Changes in hormones also affect the person’s emotions and thoughts. Puberty usually has the following psychological effects:
- heightened emotions
- frequently changing emotions
- the start of sexual thoughts and desires
- the start of sexual and romantic attractions to others
During puberty, many people begin to explore their sexuality and start to figure out whether they are homosexual, bisexual, heterosexual, or have another identity. This is totally normal, and each person’s experience is different.
Not everyone will have feelings of attraction for others, and this is nothing to worry about either. People who do not develop sexual attraction may choose to identify as asexual.
During puberty, some people begin to notice that their gender identity — how much they feel like a girl, a boy, or neither — does not match their body. If this happens, the physical changes of puberty can cause emotional distress known as gender dysphoria.
Many changes that occur during puberty are related to shifting hormone levels. Some main hormones related to puberty are:
- Testosterone. This is a primary sex hormone in males, and it gives rise to male traits, such as a deeper voice, facial hair, and muscle development. Testosterone also plays a role in female development, to a lesser extent than in males.
- Dihydrotestosterone. Called DHT, this hormone is more powerful than testosterone and present in much higher amounts during puberty. It initiates puberty in males and may also help start puberty in females.
- Estrogen. This is a primary sex hormone in females. It promotes the growth of uterus and breast tissue.
- Growth hormone. The levels of this increase during puberty, causing growth spurts in the bones and muscles, along with a rapid increase in height. A slower height increase, of less than 2 inches per year, may signal a hormone deficiency.
- Estradiol. This is present in males and females. In females, the levels of estradiol rise earlier and remain higher after puberty.
Puberty in females
One of the first signs of puberty in females tends to be a breast bud, a small amount of firm tissue under the nipple.
Emotions may fluctuate more around the time of a period, due to natural variations in hormone levels during the menstrual cycle.
Other signs of puberty include the start of vaginal discharge, body odor, and hair growing in the pubic area, under the arms, and on the legs.
Often, the hips widen, the waist becomes proportionally smaller, and extra fat develops around the stomach and buttocks. But all bodies develop differently during this time, and there is no “normal.” Each person develops their unique size and shape.
Puberty in males
In males, the earliest signs of puberty are the growth of the testicles, then the penis. The skin that surrounds the testicles, called the scrotum, becomes thinner and redder.
Body hair begins to grow, typically on the face, chest, armpits, back, and pubic area. Some people start shaving, and this can cause a rash, especially on sensitive skin. Using shaving foam or gel can help, and using an electric razor can reduce the risk of cuts.
Meanwhile, the voice starts to get lower and deeper as the voice box, or larynx, grows. A person’s voice may crack sometimes. This is normal and goes away over time. The Adam’s apple, which is the visible bump in the throat, may get bigger.
Some males also experience swelling around their nipples during puberty. This usually goes away. In around half of males, it can last a few months or a few years.
The chest and shoulders tend to become broader, and most people have growth spurts. The total amount of body fat typically starts to drop as muscle develops.
A person may start having involuntary erections and wet dreams, or ejaculation while sleeping. They may wake up with damp sheets. This can happen automatically and is not necessarily the result of sex dreams or touching the penis, though these, too, are normal.
Puberty and differences in sex development
There are many forms of DSD, and different people can have very different experiences during puberty. The Intersex Society of North America point out that some people do not know about these differences until puberty begins.
Some people do not experience all the usual, expected changes of puberty. Others may go through puberty later than usual, for example, or they might develop characteristics that do not align with their gender identity.
Some people decide to help their bodies match their gender. This might involve taking hormones or undergoing surgery, among other options. Others decide not to. There is no right or wrong answer.
DSD Teens is an online resource for young people with DSD. It provides information about the changes that happen during puberty, both inside and outside the body and brain.
The website includes a Your Puberty section, which looks at the changes that people might expect based on various conditions that affect sex development, including androgen insensitivity syndrome, gonadal dysgenesis, congenital adrenal hyperplasia, and other DSDs.
Groups such as InterACT, Advocates for Intersex Youth, are good destinations for support, resources, and community.
Early puberty affects an estimated 1–2% of children in the United States. This is when puberty begins in females younger than 8 or males younger than 9.
In most cases, early puberty is not a problem and does not require medical treatment. What experts consider normal growth and development varies widely, and it can depend on factors such as the person’s genes, environment, diet, and weight.
Common signs of early puberty are the appearance of pubic hair and body odor. A female might have early breast development, but this is often fatty tissue and may not lead to progressive growth.
In some cases, early puberty can signal a health problem, such as a genetic condition, a hormonal condition, a brain abnormality, or a problem with the testes, ovaries, or adrenal gland.
To address the issue, a doctor may recommend treatments to temporarily stop the effects of the hormones involved, especially if the underlying hormonal imbalance could cause problems later in life, such as weak bones or a lack of growth.
Meanwhile, research suggests that puberty is starting earlier now than in previous generations.
For example, a 2018 study reported that females have started to get their periods at an average age of 13, which is 3.6 months earlier than their female parents did. This can add to confusion about the typical timings of puberty.
In females, late puberty refers to breast development not beginning by age 13 or periods by age 16. In males, it refers to testicle enlargement not beginning by age 14.
Delayed puberty is usually no cause for concern. There is wide variation in what experts consider normal growth and development, and a person’s genes, environment, diet, and weight can all play a role.
Sometimes, having inadequate nutrition or a long-term illness earlier in life can delay puberty. Intense physical training, such as gymnastics, at an early age can have the same effect.
Most people with delayed puberty still go through the typical stages, just later than many of their peers.
In some cases, delayed puberty can indicate a health condition. The sex organs may produce fewer hormones — a condition called hypogonadism that can result from genetic factors, developmental disorders, or a tumor in the brain.
Puberty can be physically, mentally, and emotionally challenging. It is important to remember that it affects everyone differently — there is no one “normal” way to go through it.
Talking to friends and trusted adults can help people navigate this period of life.