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Puberty - A Guide

Published on Apr 02, 2022 and last reviewed on Nov 11, 2022   -  5 min read


Puberty is when a child becomes sexually mature and transits from childhood to adulthood. To know more, read the article below.

What Is Puberty?

Puberty is a stage of life where young boys and girls experience the process of sexual maturation. It is a continuous process consisting of several stages or steps of physical, emotional, and hormonal changes. When puberty occurs, there will be a lot of changes to the physical appearance. Biological transformations and psychological and emotional development also take place. The end result of puberty is to achieve fertility and attain a complete development of secondary sexual characteristics.

What Causes the Onset of Puberty in Boys and Girls?

The exact onset of puberty in boys and girls is not completely understood. One of many theories suggests that puberty begins when a boy or girl reaches a particular critical weight or body composition. Another study has found that a hormone known as leptin, produced in our body by the adipocytes (fat cells), has a role in initiating puberty. The leptin hormone generally increases in boys and girls just before puberty. Researchers have also said that girls who have an increased level of leptin hormone have an increased body fat percentage and undergo the early onset of puberty.

Leptin is one of the factors that makes the hypothalamus release another hormone known as gonadotropin-releasing hormone (GnRH). The GnRH hormone, in turn, signals the pituitary gland to start releasing two other hormones, namely, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These two hormones are very important as they regulate the production of estrogen and progesterone and thereby ensure sexual development.

What Is the Normal Age of Puberty in Boys and Girls?

The onset of puberty depends upon each individual, and it varies from one person to another. However, the most common age for puberty in girls is between 10 years to 14 years. Similarly, the age group is a little later in boys, that is between 12 years to 16 years.

Though these are the common age groups, there are many cases where puberty in girls starts early, during the age of 8. Recent studies have shown that our diet choices, environmental conditions, and nutritional influences adversely affect the onset of puberty during these developing times. In order to support this fact, studies have been conducted, and the findings show that the average age of onset of menstrual periods was 15 during the 1900s, whereas the average age fell down to almost 12 and a half during the 1990s.

What Physical Changes Occur in the Body During Puberty in Boys and Girls?

During puberty, the body undergoes a series of physical changes, which are typical in both boys and girls. The changes have a sequence of events that is predictable in most cases. Physicians often refer to these stages or steps of puberty as tanner stages (TS) or sexual maturity rating (SMR).



  • In most girls, the first physical change that occurs due to puberty is the starting of breast development. This usually occurs during the age of 11.

  • This early stage of breast development is called breast buds, and they continue to grow over the next few years before reaching their full shape and size.

  • Next, the growth of pubic hairs typically starts after the start of breast development. This is then followed by the development of hair in the armpit.

  • A very small percentage of girls start to develop pubic hair before breast development.

  • Girls get their first menstrual cycle almost 2 and a half years after the onset of puberty and are considered the last of all physical changes associated with puberty.

  • The achievement of fertility corresponds to a regular pattern of ovulation. In general, girls usually tend to achieve regular ovulation during the age of 13.

Certain changes happen in the body during puberty. They are:

1. Weight Changes - Puberty leads to changes in body composition and weight. In adolescent girls, the fat percentage increases on the upper and lower portions of the body and produces a curvy appearance. Boys also have an increase in body fat, but the muscle growth is too fast, so they appear more toned than girls.

2. Growth Spurt - Puberty is usually associated with a rapid increase in height. They usually last for two to three years. Statistically speaking, almost 20 % of the adult height is reached during puberty. In girls, the onset of the growth spurt is earlier by two years when compared to boys.

3. Bone Growth - Puberty is also associated with increased bone density. Studies have identified that the width of the bone gets increased first, followed by bone mineral level, and finally, the bone density. Due to the interim gap between the time of bone growth and achieving full bone density, adolescents are at a higher risk of bone fractures.

What Are the Emotional Changes That Occur during Puberty in Boys and Girls?

Puberty is a complex process involving physical, emotional, and biological changes. Emotional differences also occur during adolescence. These changes might not be the same for all adolescents and may include the following:

  • Confusion.

  • Mood swings.

  • Anxiety.

  • Being self-conscious.

  • High sensitivity.

Emotional development or change during puberty is not only associated with negative thoughts or feeling upset. However, they are also associated with positive changes that help people find their own happiness and relate to other people's feelings. The changes in physical characteristics might boost a person's confidence and change their approach towards others.

What Are the Conditions Associated With Normal Puberty?

Puberty is a natural phase of everyone's life, but certain illnesses or medical conditions appear during puberty. Though they are not usually severe, they might be a cause for concern in certain cases. Some of these conditions include:

  • Anemia.

  • Acne.

  • Gynecomastia.

  • Scoliosis.

  • Vision changes.

  • Dysfunctional uterine bleeding.

  • Musculoskeletal injuries.


Puberty is a natural process, and it is perfectly normal for both the children and the parent to be anxious about it. Various healthcare professionals guide the children and their parents to help them overcome the anxiety about this stage of life. In addition, the onset of puberty might differ from one person to another, but if any severe conditions cause an extensive delay or early onset of puberty, it is important to reach out to your doctor to get medical attention.

Last reviewed at:
11 Nov 2022  -  5 min read




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