Puberty — Early, Late & the
Menstrual Cycle
A concise clinical reference covering normal puberty, precocious puberty screening, and menstrual cycle assessment for general practitioners working with adolescents aged 10–19.
What Is Puberty?
Puberty is the normal developmental process where a child matures into reproductive adulthood, driven by activation of the hypothalamic–pituitary–gonadal (HPG) axis.
Puberty in Girls (Typical Sequence)
Normal age range: 8–13 years
- Thelarche (breast budding) — first sign
- Pubarche — pubic/axillary hair
- Growth spurt — early in puberty
- Menarche — ~2–3 years after thelarche (Tanner Stage IV)
- Cycles may be irregular for up to 2 years
- Peak height velocity: girls ~11–12 years
Puberty in Boys (Typical Sequence)
Normal age range: 9–14 years
- Testicular enlargement (>4 mL) — first sign
- Penile growth
- Pubic hair development
- Growth spurt — later than in girls
- Voice deepening & facial hair
- Peak height velocity: boys ~13–14 years
Used clinically to track progression. Stage I = prepubertal; Stage V = adult maturity.
| Stage | People with Testes | People with Ovaries |
|---|---|---|
| Stage 1 | Basal growth; no penile or testicular enlargement; no pubic hair | Basal growth; papillar elevation of the breasts; no pubic hair |
| Stage 2 | Basal growth continues; minimal pubic hair; slight testicular enlargement (size 4 mL or long axis 2.5–3.2 cm) | First growth spurt; breast bud development and areolar growth; labial pubic hair emergence |
| Stage 3 | First growth spurt; emergence of pubic hair over pubis; continued testicular enlargement; penis lengthens; gynecomastia common | Rapid growth rate; enlargement of breasts and areolae; pubic hair growth across mons pubis/axillae |
| Stage 4 | Rapid growth rate; pubic hair spreads; continued penis (length and girth) and testicular enlargement; axillary hair; voice deepens | Growth rate slows; secondary areolar mound formation; coarse pubic hair distribution spreads; menarche may begin |
| Stage 5 | Usually achieved maximum height; pubic hair distribution of adult; facial hair development begins | Usually achieved maximum height; adult breast shape with minimisation of areolar mounds; pubic hair distribution of adult |
When to Refer to a PaediatricianNo puberty: girls by 13 years / boys by 14 years. No menarche by 15 years. Puberty starting too early (precocious). Rapid or abnormal progression. Always assess growth charts, pubertal staging, and psychosocial impact. Reassurance is often enough in normal cases.
Precocious Puberty Screening
Precocious puberty is defined as pubertal signs before age 8 in girls or age 9 in boys. Use this structured 5-step screening process.
Step 1: Age Check
Is the patient a girl <8 years ❗ or a boy <9 years ❗? If YES → proceed to screening.
Step 2: Early Signs Check
Girls: Breast development · Pubic/axillary hair · Vaginal bleeding/discharge · Rapid height growth
Boys: Testicular enlargement · Penile growth · Pubic/axillary hair · Voice deepening
If ≥1 sign present → continue to Step 3.
Step 3: Red Flags — Urgent Referral
☐ Age <6 years (girls) or <7 years (boys) · ☐ Rapid progression (months, not years) · ☐ Neurological symptoms (headache, vision changes) · ☐ Virilisation (severe acne, deep voice in girls) · ☐ Exposure to hormone creams/medications
If ANY checked → URGENT referral
Step 4: Quick Exam
☐ Plot height & growth velocity · ☐ Tanner staging · ☐ Look for asymmetry (testes, breasts) · ☐ Signs of systemic illness
Step 5: Initial Actions (If Suspected)
Order: Bone age X-ray (if available) · LH, FSH · Estradiol (girls) / Testosterone (boys)
Refer to: Paediatrician / Endocrinology
Clinical TipEarly puberty = growth spurt first, short adult height later. Always take a brief exposure history (hair creams, hormone products).
Menstrual Cycle Assessment
Document cycle history at every visit using PALM-COEIN classification for abnormal uterine bleeding. Measured from Day 1 of bleeding → next Day 1.
Normal Parameters (Adolescents)
- Cycle length: 21–45 days
- Duration of bleeding: 2–7 days
- Blood loss: ≤80 mL (≈ 3–6 pads/day)
- Irregular cycles normal for up to 2 years after menarche
Abnormal — Needs Evaluation
- Cycles: <21 days or >45 days, or absent >90 days
- Bleeding: >7 days or soaking pad every 1–2 hours
- Severe pain not responding to NSAIDs
- Dizziness, fatigue (possible anaemia)
Menstrual Phase (Days 1–5)
Shedding of the uterine lining. Low estrogen & progesterone. Bleeding occurs.
Follicular Phase (Days 1–13)
Overlaps with menstruation. FSH stimulates follicle development. Estrogen rises → endometrium thickens.
Ovulation (≈ Day 14)
Triggered by an LH surge. Egg released from the ovary. Most fertile period.
Luteal Phase (Days 15–28)
Corpus luteum produces progesterone. Prepares the uterus for implantation. If no pregnancy → hormone levels fall → next period.
Abnormal Uterine Bleeding
Heavy menstrual bleeding (HMB), oligomenorrhea, or amenorrhea warrants evaluation. Common causes in adolescents: anovulation, PCOS, thyroid disease, and pregnancy.
Dysmenorrhea
Primary dysmenorrhea is common and manageable. Treat with NSAIDs (first-line) and combined hormonal contraception if needed. Persistent or severe pain unresponsive to treatment warrants investigation for endometriosis.
Coagulopathy Screen
Always consider coagulopathy (especially von Willebrand disease) in adolescents presenting with heavy menstrual bleeding from menarche — screen with a validated bleeding score before further investigation.
Clinical Tips — Always AskAge at menarche · Cycle regularity · Flow (pads/day) · Pain severity. Use menstrual tracking apps or calendars. Screen for: Pregnancy (if sexually active) · PCOS · Thyroid Disease · Von Willebrand Disease. Anovulatory cycles are common early after menarche due to an immature hormonal axis.
HEADSS 3.0 Assessment
Full step-by-step psychosocial assessment guide for adolescent consultations.
- ↗Access the full HEADSS 3.0 interview sequence
- ↗Integrate into every adolescent consultation
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Yuh Good: Barbados Adolescent Health Hub @ 2026