Delayed Puberty in Teenage Boys: Causes, Evaluation, and Outlook

Puberty onset varies widely. By age 17, most males have started, but absence of signs warrants evaluation. Common reasons include:

1. Constitutional Delay (Genetic)

"Late bloomer" pattern—often runs in families. Growth and development eventually normalize without intervention.

2. Medical Conditions

• Klinefelter syndrome (47,XXY): Testicular dysfunction, low testosterone.
• Kallmann syndrome: Gonadotropin-releasing hormone deficiency with anosmia.
• Hypothyroidism: Slows overall maturation.
• Chronic illnesses: IBD, cystic fibrosis, malnutrition, eating disorders.

3. Lifestyle Factors

• Severe malnutrition or eating disorders.
• Obesity (can alter hormone metabolism).
• Excessive exercise with energy deficit.

When to See a Doctor

If no testicular enlargement by age 14, or no pubertal progression by 17, consult a pediatric endocrinologist. Evaluation includes history, physical, hormone levels (LH, FSH, testosterone), and possibly genetic testing. Treatment (e.g., testosterone therapy) is individualized.