21.1 Adolescent Health & Puberty

Sexual Maturity Rating: Tanner Staging

Adolescent physical development is graded using the Tanner staging system (Sexual Maturity Rating, SMR), which describes five sequential stages (I-V) for genital or breast development and for pubic hair growth. On a best-of-five written paper, examiners frequently give a brief physical description and ask the candidate to identify the correct stage, so the defining feature of each stage — not just the stage number — must be memorized.

Male Genital Development

• Stage 1: Prepubertal; testicular volume under 4 mL, with testes, scrotum, and penis proportioned as in early childhood.
• Stage 2: Testicular and scrotal enlargement (testicular volume 4 mL or more) with reddening and a texture change of the scrotal skin; penis size is essentially unchanged. This is the first clinical sign of male puberty.
• Stage 3: The penis lengthens, with further testicular and scrotal growth.
• Stage 4: The penis increases further in length and breadth with development of the glans; scrotal skin darkens further.
• Stage 5: Adult genital size and shape.

Female Breast Development

• Stage 1: Prepubertal, with only nipple elevation.
• Stage 2: Breast budding — the first clinical sign of female puberty — with elevation of the breast and papilla as a small mound and enlargement of the areolar diameter.
• Stage 3: Further enlargement of breast and areola without separation of their contours.
• Stage 4: The areola and papilla project to form a secondary mound above the level of the breast.
• Stage 5: Mature breast; the areola recesses to the general contour of the breast while the papilla continues to project.

Pubic Hair (Both Sexes)

• Stage 1: No pubic hair (vellus only, similar to the abdomen).
• Stage 2: Sparse, fine, lightly pigmented, downy hair.
• Stage 3: Darker, coarser, curlier hair spreading sparsely over the pubis.
• Stage 4: Adult-type hair in quality, but not yet spread to the medial thighs.
• Stage 5: Adult quantity and distribution, spreading to the medial thighs.

Exam trap: genital/breast stage and pubic-hair stage are graded and reported on separate axes — a child can be genital stage 3 but pubic-hair stage 2 (for example, in some forms of precocious puberty driven by isolated adrenarche rather than true central puberty). Always answer for the specific axis the question stem asks about.

Normal Puberty Timing, and Precocious vs. Delayed Puberty

Puberty is triggered by reactivation of the hypothalamic-pituitary-gonadal (HPG) axis after a period of childhood quiescence. On average, girls begin puberty (thelarche) around 8-13 years, with menarche following roughly two to two-and-a-half years later (average approximately 12-13 years); boys begin puberty (testicular enlargement) around 9-14 years, typically one to two years later than girls on average.

• Precocious puberty: onset of secondary sexual characteristics before age 8 in girls or age 9 in boys.
• Delayed puberty: absence of breast development by age 13 in girls, absence of menarche by age 15-16, or absence of testicular enlargement by age 14 in boys.

The detailed endocrine work-up for abnormal timing — bone-age radiographs, basal and GnRH-stimulated LH/FSH, and distinguishing central (gonadotropin-dependent) from peripheral (gonadotropin-independent) causes — is covered in the endocrinology chapter of this guide. For this chapter, the exam-relevant skill is recognizing when Tanner staging is abnormal for chronological age and knowing that abnormal timing triggers referral rather than reassurance.

The HEADSSS Psychosocial Interview

The HEADSSS interview (also written HEEADSSS when Eating is expanded as its own letter) is the structured framework for the adolescent psychosocial history, used at every well-adolescent visit:

Questions progress deliberately from least to most sensitive (Home toward Safety/Suicide/Sexuality), a sequence designed to build rapport before probing threatening topics. The interview should be conducted with the adolescent alone, without the parent present, after the clinician has explained the limits of confidentiality (developed further in the ethics section of this chapter).

Menstruation, Gynecomastia, and Mental Health Screening

Menstrual health topics appear frequently in adolescent vignettes:

• Primary amenorrhea: no menarche by age 15 with otherwise normal pubertal development, or no menarche within 3 years of thelarche.
• Primary dysmenorrhea: crampy pain with ovulatory cycles, typically beginning 6-12 months after menarche; NSAIDs are first-line. Progressive or severe pain should prompt evaluation for secondary causes such as endometriosis or müllerian anomalies.
• Irregular cycles in the first 1-2 years after menarche are often physiologic (anovulatory) and do not require work-up unless accompanied by heavy bleeding, prolonged amenorrhea, or signs of hyperandrogenism.

Gynecomastia (palpable breast tissue in boys) is physiologic in up to 60% of pubertal boys — typically bilateral, tender, and under 4 cm in diameter, resolving spontaneously within 1-2 years. Red flags warranting further evaluation include unilateral enlargement, rapid growth, a fixed hard mass, or persistence beyond mid-puberty, to exclude medication effects, hyperthyroidism, testicular tumor, or Klinefelter syndrome (detailed work-up is covered in the endocrinology chapter).

Structured screening tools complement the HEADSSS domains:

• PHQ-A (Patient Health Questionnaire modified for Adolescents) screens for depression.
• CRAFFT screens for substance use (Car, Relax, Alone, Forget, Friends, Trouble).

Any disclosure of suicidal plan or intent requires immediate risk assessment and safety intervention; confidentiality is overridden to protect life.

Common Adolescent Health Issues: Eating Disorders and Confidentiality

Eating disorder red flags the exam expects a candidate to recognize include: a fall-off in growth-curve percentile (weight or BMI crossing down through percentile lines), amenorrhea in a previously menstruating girl, orthostatic hypotension or bradycardia, lanugo hair, dental enamel erosion (suggestive of self-induced vomiting), calluses on the dorsum of the hand (Russell sign), preoccupation with body image or weight despite a normal or low weight, and compulsive or excessive exercise. The brief SCOFF questionnaire (Sick, Control, One stone, Fat, Food) is a validated screening tool referenced in the adolescent-medicine literature and can appear as a distractor or correct answer in screening-tool questions.

Confidentiality is central to effective adolescent care: adolescents who believe their disclosures will automatically be shared with parents are less likely to seek care for sensitive issues (mental health, sexuality, substance use) and less likely to disclose honestly when they do present. Best practice is to see the adolescent for part of every visit without the parent present, to explicitly state what will and will not remain confidential before asking the sensitive questions, and to apply those limits consistently — safety, suspected abuse, and suicidal risk override confidentiality, as detailed in the companion ethics section of this chapter.