Delayed Puberty: Symptoms, Types, Causes and Treatment

Delayed puberty is a common concern among adolescents and their families, often prompting medical evaluation due to worries about growth, development, and social integration. Although most cases are benign, understanding the symptoms, types, underlying causes, and treatment options is crucial for healthcare providers, parents, and affected teenagers. This comprehensive guide synthesizes the latest research to provide a clear and evidence-based overview of delayed puberty.

Symptoms of Delayed Puberty

When puberty doesn’t start within the expected age range, it can be distressing for both adolescents and their families. Recognizing the key symptoms early is essential for timely diagnosis and management. While the average age for the onset of puberty varies, delays are typically defined by the absence of specific developmental milestones beyond certain ages.

Symptom	Description	Typical Threshold Age	Source(s)
Absent breast development (girls)	No breast budding (thelarche)	>13 years	2 6 8
Absent testicular enlargement (boys)	Testicular volume <4 mL	>14 years	2 6 8
Absent menarche (girls)	No first menstrual period	>15 years	2 6
Stunted growth or delayed growth spurt	Height below expected percentile	N/A	3 9

Table 1: Key Symptoms

What Are the Symptoms?

Delayed puberty most commonly presents with a lack of secondary sexual characteristics:

• Girls: The first sign is usually breast development (thelarche). Failure to develop breasts by age 13, or not having a menstrual period (menarche) by age 15, is considered delayed. Some girls may have breast development but fail to menstruate, indicating possible underlying structural or hormonal issues 2 6 8.
• Boys: The initial sign is testicular enlargement. If testicular volume remains less than 4 mL or length less than 2.5 cm by age 14, puberty is considered delayed 2 6 8.
• Both sexes: A noticeable lack of growth spurt or continued short stature compared to peers often accompanies delayed puberty. This may be the presenting concern for families 3 9.

Additional Clinical Features

• Delayed development of pubic and axillary hair
• Lack of voice deepening in boys or lack of breast growth in girls
• Psychological distress or social withdrawal due to perceived differences from peers
• Potentially, signs of underlying health problems such as chronic illness, if present

Why Early Recognition Matters

Timely recognition of delayed puberty allows for:

• Early identification of treatable underlying causes
• Prevention of psychosocial complications (e.g., low self-esteem, anxiety)
• Timely intervention to ensure optimal growth and bone health

Types of Delayed Puberty

Delayed puberty is not a single condition but a spectrum, classified by underlying mechanisms. Understanding these types is pivotal for diagnosis and management.

Type	Characteristics	Gender Predominance	Source(s)
Constitutional Delay (CDGP)	Benign, self-limited delay in growth/puberty	Boys	3 7 9
Functional Hypogonadotropic Hypogonadism (FHH)	Delayed but spontaneous puberty due to non-permanent hypothalamic-pituitary suppression	Boys	3 10
Permanent Hypogonadotropic Hypogonadism	Failure of GnRH secretion/action; puberty does not occur	Both	2 4 13
Hypergonadotropic Hypogonadism	Gonadal failure (ovaries/testes); high gonadotropins	Girls	2 5 8

Table 2: Major Types of Delayed Puberty

Constitutional Delay of Growth and Puberty (CDGP)

• Definition: The most common and benign form, CDGP is a variation of normal development where puberty and growth are delayed but eventually occur spontaneously.
• Features: Often familial; growth and pubertal milestones are postponed, but final height and sexual maturity are usually within normal limits 3 7 9.
• Demographics: More frequent in boys; often a positive family history 3 9.

Functional Hypogonadotropic Hypogonadism (FHH)

• Definition: Pubertal delay due to temporary suppression of the hypothalamic-pituitary-gonadal (HPG) axis, often secondary to chronic illnesses, undernutrition, or psychological stress 3 10.
• Features: Puberty may eventually progress if the underlying condition is addressed.
• Examples: Chronic systemic diseases (e.g., celiac disease, inflammatory bowel disease), eating disorders, intense athletic activity.
• Genetic Factors: Recent studies suggest that certain gene mutations (e.g., IGSF10) may impact GnRH neuron migration, underlying some cases of FHH and CDGP 10.

Permanent Hypogonadotropic Hypogonadism

• Definition: A rare, lifelong deficiency of GnRH secretion or action, leading to persistent failure of puberty unless treated 2 4 13.
• Causes: Congenital genetic defects (e.g., Kallmann syndrome), acquired hypothalamic or pituitary damage.

Hypergonadotropic Hypogonadism

• Definition: Gonadal (ovary/testis) failure results in high levels of gonadotropins (FSH, LH) but low sex steroids. Puberty does not occur spontaneously 2 5 8.
• Causes: Turner syndrome in girls, Klinefelter syndrome in boys, gonadal dysgenesis, previous chemotherapy/radiation.

Other Classifications

• Eugonadotropic delayed puberty: Normal gonadotropin levels with delayed progression; uncommon 2.
• Mixed or unclassified cases: A small proportion do not fit neatly into established categories 3.

Causes of Delayed Puberty

The causes of delayed puberty are diverse, ranging from benign familial traits to significant underlying diseases. Identifying the cause is essential for appropriate management.

Cause Category	Examples	Key Features	Source(s)
Constitutional/Genetic	CDGP, family history, ethnic variation	Self-limited, familial	3 7 9
Functional Suppression	Chronic illness, undernutrition, stress	Reversible if cause treated	3 10 14
Primary Gonadal Failure	Turner syndrome, Klinefelter syndrome, chemo/radiation	High gonadotropins, no sex steroids	2 5 8
Central Hypogonadism	Kallmann syndrome, pituitary disorders, CHH	Low/normal gonadotropins	2 4 13
Structural Abnormalities	Congenital genital tract anomalies (esp. girls)	Amenorrhea with breast development	1 2
Environmental Factors	Endocrine disruptors, excessive exercise	May delay or alter timing	13

Table 3: Major Causes of Delayed Puberty

Constitutional and Genetic Causes

• Constitutional Delay: Often inherited, with a strong family history. Both parents can contribute to this trait 3 9.
• Genetic Mutations: Specific gene defects (e.g., IGSF10, over 30 genes in CHH) can cause delayed or absent puberty, with recent research uncovering distinct genetic architectures for CDGP versus CHH 4 10.

Functional Suppression of the HPG Axis

• Chronic Disease: Conditions such as inflammatory bowel disease, diabetes, celiac disease, or chronic kidney/lung disease can suppress the HPG axis, causing functional hypogonadotropic hypogonadism 3 10 14.
• Nutritional Deficiency: Undernutrition, eating disorders, or excessive physical activity (common in athletes) may delay puberty.
• Psychosocial Stress: Severe emotional stress can sometimes delay puberty 13.

Primary Gonadal Failure (Hypergonadotropic Hypogonadism)

• Girls: Most commonly due to Turner syndrome or ovarian dysgenesis 2 5 8.
• Boys: Klinefelter syndrome, testicular injury, or genetic causes.
• Acquired Causes: Gonadal damage from chemotherapy or radiation.

Central Hypogonadism (Hypogonadotropic Hypogonadism)

• Congenital: Kallmann syndrome (often with impaired smell), congenital hypopituitarism.
• Acquired: Tumors, trauma, infections, or infiltrative diseases affecting the hypothalamus or pituitary 2 4 13.

Structural Abnormalities

• Girls: Genital tract anomalies, such as imperforate hymen or Müllerian agenesis, can present as amenorrhea despite breast development 1 2.

Environmental Factors

• Endocrine Disruptors: Exposure to chemicals that disrupt hormonal systems may play a role in altering pubertal timing 13.
• Secular Trends: Changes in nutrition and environment have shifted the average age of puberty in recent decades.

Treatment of Delayed Puberty

Management of delayed puberty is highly individualized, depending on the underlying cause, psychological impact, and the wishes of the adolescent and their family. The primary goals are to induce or support normal puberty, optimize growth, and address psychosocial well-being.

Treatment Approach	Indication	Main Interventions	Source(s)
Observation/Reassurance	CDGP, mild cases	Monitoring, education, support	3 7 14
Sex Steroid Therapy	Persistent CDGP, psychological distress	Low-dose testosterone (boys), oral estradiol (girls)	2 11 12 14
Treat Underlying Illness	Functional suppression	Address chronic disease, improve nutrition	3 10 14
Hormone Replacement	Permanent hypogonadism	Gonadotropins, sex steroids	2 13 14
Psychological Support	All cases as needed	Counseling, peer support	14

Table 4: Treatment Strategies

Observation and Reassurance

• CDGP: Most adolescents with constitutional delay require only reassurance, as spontaneous puberty is expected. Regular monitoring of growth and development is essential 3 7 14.

Sex Steroid Therapy

• Indications: Considered for boys older than 14 or girls older than 13 with significant distress, social withdrawal, or low self-esteem 2 12 14.
• Boys: Low-dose testosterone (oral or intramuscular) for 3–6 months can jump-start puberty, stimulate growth, and improve body composition 2 11 12 14.
  • Studies show increased height, fat-free mass, and pubertal progression after testosterone therapy 11 12.
  • In specific populations (e.g., Duchenne muscular dystrophy), testosterone can improve bone density and motor function 15.
• Girls: Oral or transdermal estradiol is used to initiate breast development and eventual menstruation. Dosing is typically started low and escalated over 2 years to mimic normal puberty 2 14.
• Monitoring: Regular follow-up to assess progress and possible side effects is required.

Treating Underlying Illness

• Functional Suppression: Addressing chronic disease, improving nutrition, or reducing excessive exercise/stress can restore normal pubertal progression 3 10 14.
• Multidisciplinary Care: May involve pediatricians, endocrinologists, dietitians, and mental health professionals.

Hormone Replacement for Permanent Hypogonadism

• Gonadotropins or GnRH Therapy: Used for inducing puberty in central hypogonadism, especially when fertility is a concern 2 13 14.
• Sex Steroids: Continued until full adult sexual maturity is achieved.

Psychological and Social Support

• Counseling: Address emotional and psychological impact, which can be significant in adolescents with delayed puberty 14.
• Peer Support: Connecting with others experiencing similar challenges can help normalize the experience.

Emerging and Novel Therapies

• Kisspeptin Agonists, Newer Hormonal Regimens: Research is ongoing into more physiological ways to induce puberty, especially for hypogonadotropic hypogonadism 13.
• Reassessment: Some boys with idiopathic hypogonadotropic hypogonadism may experience spontaneous reversal after sex steroid treatment, emphasizing the need for ongoing evaluation 13.

Conclusion

Delayed puberty is a multifaceted condition that requires careful assessment and a tailored approach. While most cases are benign and self-limited, distinguishing between constitutional delay and underlying pathology is crucial for optimal outcomes.

Key Points:

• Symptoms include absent breast development or testicular enlargement, delayed menarche, and stunted growth.
• Types range from constitutional delay (most common), functional suppression, permanent hypogonadotropic and hypergonadotropic hypogonadism, to structural anomalies.
• Causes can be genetic, functional (e.g., chronic illness, undernutrition), primary gonadal or central (hypothalamic/pituitary) failure, or environmental.
• Treatment is individualized and may involve reassurance, short-term sex steroid therapy, treating underlying causes, full hormone replacement, and psychological support.

Early recognition, accurate diagnosis, and supportive care can help adolescents with delayed puberty achieve healthy physical and emotional development 2 3 7 14.