My teenager hasn't started puberty. Is this normal?

Delayed puberty is defined as:

• Girls: No breast development by age 13.
• Boys: No enlargement of testicles by age 14.

What is "Constitutional Delay"?

This is the most common cause (about 60-70% of cases). These teens are "late bloomers." They are healthy, but their internal clock is running slow. There is often a family history of a parent starting puberty late ("I didn't shave until I was 16"). These teens will eventually start puberty on their own and catch up.

What are other causes?

• Chronic Illness: Celiac disease, Crohn's disease, or cystic fibrosis (the body is too stressed to start puberty).
• Malnutrition/Excessive Exercise: Common in athletes or those with eating disorders (anorexia).
• Hypogonadism: The body cannot make sex hormones due to genetic conditions (like Turner Syndrome in girls or Klinefelter Syndrome in boys) or pituitary damage.

How is it evaluated?

• Physical Exam: To accurately stage puberty (Tanner Staging).
• Blood Tests: To distinguish between a "late bloomer" and permanent hypogonadism.
• Bone Age X-ray: To see growth potential.

Is treatment needed?

• Late Bloomers: Usually, reassurance is all that is needed. Sometimes, a short course (3-6 months) of low-dose testosterone (for boys) or estrogen (for girls) is given to "jump-start" puberty and help the teen feel more like their peers.
• Permanent Conditions: Lifelong hormone replacement therapy is required.