{"id":4422430,"date":"2025-01-11T18:30:15","date_gmt":"2025-01-12T00:30:15","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/normal-puberty\/"},"modified":"2025-01-13T07:03:48","modified_gmt":"2025-01-13T13:03:48","slug":"normal-puberty","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/normal-puberty\/","title":{"rendered":"Normal Puberty"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">NORMAL PUBERTY<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Timing of Puberty<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition<\/strong>: Puberty is a biologic transition in which secondary sex characteristics develop, a linear growth spurt occurs, fertility is realized, and psychosocial changes ensue.<\/li>\n\n\n\n<li><strong>Adrenarche vs. Gonadarche<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Adrenarche<\/strong>: Maturation of adrenal androgens, usually earlier than gonadal maturation.<\/li>\n\n\n\n<li><strong>Gonadarche<\/strong>: Maturation of the hypothalamic\u2013pituitary\u2013gonadal (HPG) axis.<\/li>\n\n\n\n<li><strong>Thelarche<\/strong>: Pubertal breast development.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Average Onset<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Girls (White)<\/strong>: Mean onset ~10.6 years (range 7\u201313).<\/li>\n\n\n\n<li><strong>Girls (African American)<\/strong>: Mean onset ~8.9 years (range 6\u201313).<\/li>\n\n\n\n<li><strong>Boys<\/strong>: Mean onset ~11 years (range 9\u201314); some African American boys start as early as 8\u20139 years.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Determinants<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Body weight (adipose signals such as leptin) can influence puberty onset.<\/li>\n\n\n\n<li>Multiple factors regulate hypothalamic GnRH pulse generator activation.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Hormonal Control<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HPG Axis<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Increased gonadotropins (LH, FSH) \u2192 gonadal (testis\/ovary) secretion of sex steroids (androgens, estrogens).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Adrenal Involvement<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Corticotropin (ACTH) + an unknown \u201cadrenal androgen\u2013stimulating factor\u201d \u2192 adrenal reticular zone \u2192 adrenal androgens.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Sex Steroids<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Androgens<\/strong> + <strong>Estrogens<\/strong> from gonads and adrenal glands \u2192 changes in hair growth, growth spurt, body composition, and epiphyseal maturation\/fusion.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Growth Spurt and Body Composition<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Height Increase<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Pubertal growth spurt accounts for ~18% of final adult height.<\/li>\n\n\n\n<li>Peak height velocity in <strong>girls<\/strong> ~8.3 cm\/year at ~11.5 years; in <strong>boys<\/strong> ~9.5 cm\/year at ~13.5 years.<\/li>\n\n\n\n<li>Boys generally end up ~10 cm taller on average due to later onset &amp; longer growth period.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Hormones Involved<\/strong>:\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/myendoconsult.com\/learn\/evaluation-of-adult-growth-hormone-deficiency\/\"  data-wpil-monitor-id=\"200\">Growth Hormone<\/a> (GH), Insulin-like Growth Factor 1 (IGF-1), Estrogen (both sexes), and Testosterone (in boys).<\/li>\n\n\n\n<li><a href=\"https:\/\/myendoconsult.com\/learn\/serum-igf-1-to-igfbp-3-molar-ratio\/\"  data-wpil-monitor-id=\"203\">Serum IGF-1<\/a> peaks during puberty and remains high ~2 years after peak growth velocity.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>U : L Ratio<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Ratio of upper to lower body segment. Decreases from ~1.7 at birth to ~1.0 by 10 years; ~0.92 in White adults, ~0.85 in African American adults.<\/li>\n\n\n\n<li><strong>Hypogonadism<\/strong> (delayed epiphyseal fusion) \u2192 prolonged limb growth \u2192 lower U : L ratio (eunuchoid habitus).<\/li>\n\n\n\n<li><strong>Excess estrogen<\/strong> \u2192 advanced <a href=\"https:\/\/myendoconsult.com\/learn\/bone-age-assessment\/\"  data-wpil-monitor-id=\"204\">bone age<\/a>, short adult stature, higher U : L ratio.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Bone Mass Changes<\/strong>:\n<ul class=\"wp-block-list\">\n<li>50% of total body calcium is laid down in bone during puberty. Boys generally end up with more skeletal mass; girls have wider hips.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Body Composition<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Men have ~50% more lean <a href=\"https:\/\/myendoconsult.com\/learn\/bmi-calculator\/\"  data-wpil-monitor-id=\"201\">body mass<\/a> and skeletal mass; women have ~2\u00d7 body fat (hips, upper arms, thighs, back).<\/li>\n\n\n\n<li><strong>Cardiovascular Changes<\/strong>: \u2191aerobic reserve.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Tanner Stages (General)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Developed by <strong>Marshall and Tanner<\/strong>: 5 stages describing external pubertal development.<\/li>\n\n\n\n<li>Girls: <strong>Breast (thelarche)<\/strong> + <strong>Pubic hair<\/strong> staging.<\/li>\n\n\n\n<li>Boys: <strong>Genital<\/strong> + <strong>Pubic hair<\/strong> staging.<\/li>\n\n\n\n<li><strong>Stage 1<\/strong>: Prepubertal; <strong>Stage 5<\/strong>: Adult.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">FEMALE PUBERTY<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Main Pubertal Events<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Height Velocity Increase<\/strong> (often first sign).<\/li>\n\n\n\n<li><strong>Breast Development (Thelarche)<\/strong>: Under ovarian estrogen control.<\/li>\n\n\n\n<li><strong>Pubic + Axillary Hair<\/strong> Growth: Under androgens from ovary + adrenal.<\/li>\n\n\n\n<li><strong>Menarche<\/strong>: Onset of menses (usually around <a href=\"https:\/\/myendoconsult.com\/learn\/endocrine-reviews-reproductive-endocrinology\/tanner-staging\/\"  data-wpil-monitor-id=\"202\">Tanner stage<\/a> 4).<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Thelarche (Breast Development)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tanner Stage 1<\/strong>: Prepubertal (elevated papilla only).<\/li>\n\n\n\n<li><strong>Stage 2<\/strong>: \u201cBreast bud\u201d with enlargement of areola diameter + small mound.\n<ul class=\"wp-block-list\">\n<li>Mean onset of stage 2 ~10.3 years (White) vs. ~9.5 years (African American).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Stage 3<\/strong>: Further enlargement of breast\/areola, no contour separation.<\/li>\n\n\n\n<li><strong>Stage 4<\/strong>: Areola + papilla project above breast, forming a secondary mound.<\/li>\n\n\n\n<li><strong>Stage 5<\/strong>: Mature adult breast with areola recession, only papilla projects.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Pubic Hair Development<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tanner Stage 1<\/strong>: Vellus-type hair, no difference from abdominal wall.<\/li>\n\n\n\n<li><strong>Stage 2<\/strong>: Sparse, slightly pigmented, slightly curled hair along labia.\n<ul class=\"wp-block-list\">\n<li>Mean onset of stage 2 ~10.4 years (White) vs. ~9.4 years (African American).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Stage 3<\/strong>: Hair coarser, darker, curlier, sparsely over pubic region.<\/li>\n\n\n\n<li><strong>Stage 4<\/strong>: Adult-type hair but covers a smaller area; not yet on medial thighs.<\/li>\n\n\n\n<li><strong>Stage 5<\/strong>: Adult in quantity, type, distribution onto medial thighs.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Menarche and Ovarian Changes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Menarche<\/strong>: Average onset ~12.8 years (White US), 6 months earlier in African American girls.\n<ul class=\"wp-block-list\">\n<li>Usually 1\u20133 years after pubertal onset (Tanner stage 4).<\/li>\n\n\n\n<li>Initial cycles may be anovulatory, irregular.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ovarian Maturation<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Follicles<\/strong> >4 mm develop, ovarian volume \u2191 from &lt;2 mL to ~2.8\u201315 mL.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Other Changes<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Vaginal mucosa: Red, glistening \u2192 thicker, cornified epithelium.<\/li>\n\n\n\n<li>Uterus grows from ~3 cm to 8 cm length.<\/li>\n\n\n\n<li>Axillary hair ~12 years in ~90% African American girls vs. ~70% White girls.<\/li>\n\n\n\n<li>Acne, caused by ovarian + adrenal androgens, can appear early.<\/li>\n\n\n\n<li>Facial structural changes (nose, mandible, maxilla).<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">MALE PUBERTY<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Main Pubertal Events<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Height Velocity Increase<\/strong>.<\/li>\n\n\n\n<li><strong>Genital Development<\/strong> (testicular enlargement, penile growth) \u2013 under LH\/FSH stimulation \u2192 testosterone.<\/li>\n\n\n\n<li><strong>Pubic + Axillary Hair<\/strong> \u2013 from testicular + adrenal androgens.<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>First sign typically <strong>testicular enlargement<\/strong>. This occurs ~6 months after breast budding onset in girls.<\/li>\n\n\n\n<li>Normal onset range for boys is <strong>9\u201314 years<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Testicular Development<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Testicular Volume<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Prepubertal ~1\u20133 mL.<\/li>\n\n\n\n<li>Puberty onset typically recognized at ~4 mL.<\/li>\n\n\n\n<li>Adult ~29 mL average (slightly larger on right).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Growth primarily from <strong>seminiferous tubules<\/strong> expansion.<\/li>\n\n\n\n<li><strong>Leydig Cells<\/strong>: Appear under LH stimulation, produce testosterone.<\/li>\n\n\n\n<li><strong>Spermatogenesis<\/strong> starts ~11\u201315 years.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Penile Growth<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Measuring<\/strong>: Flaccid + stretched length. ~6 cm prepubertal, ~12 cm in adult White men.<\/li>\n\n\n\n<li><strong>Glans<\/strong> and overall length + width enlarge through <strong>Tanner stages<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Tanner Stages for Male Genitalia and Pubic Hair<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Genital Stage 1<\/strong>: Childhood size penis, testes, scrotum.\n<ul class=\"wp-block-list\">\n<li><strong>Pubic Hair Stage 1<\/strong>: Vellus hair, no different from abdominal wall.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genital Stage 2<\/strong>: Enlargement of testes\/scrotum (reddening, texture change).\n<ul class=\"wp-block-list\">\n<li><strong>Pubic Hair Stage 2<\/strong>: Sparse, lightly pigmented hair at base of penis.<\/li>\n\n\n\n<li>Average age ~11.2 for stage 2 genital changes.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genital Stage 3<\/strong>: Penile length > width growth; further testis + scrotum enlargement.\n<ul class=\"wp-block-list\">\n<li><strong>Pubic Hair Stage 3<\/strong>: Darker, coarser, curlier hair spread sparsely.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genital Stage 4<\/strong>: Increased penile length + width, development of glans; scrotum\/testes enlarge further, scrotal skin darkens.\n<ul class=\"wp-block-list\">\n<li><strong>Pubic Hair Stage 4<\/strong>: Adult-type hair, smaller area, not on medial thighs.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genital Stage 5<\/strong>: Adult size\/shape of genitalia.\n<ul class=\"wp-block-list\">\n<li><strong>Pubic Hair Stage 5<\/strong>: Adult in quantity\/type, spread to medial thighs.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Other Male Pubertal Changes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Voice Deepening<\/strong>: Larynx + vocal cords enlarge between Tanner stages 3 and 4; adult voice by ~15 years.<\/li>\n\n\n\n<li><strong>Facial Hair<\/strong>: Starts around corners of upper lip\/cheek, eventually covering cheeks\/chin after Tanner stage 5.<\/li>\n\n\n\n<li><strong>Axillary Hair<\/strong>: Appears ~14 years.<\/li>\n\n\n\n<li><strong>Acne<\/strong>: ~12 years onset (range 9\u201315), from adrenal + testicular androgens.<\/li>\n\n\n\n<li><strong>Pubertal Gynecomastia<\/strong>: ~50% of boys, average age ~13, usually resolves in 1\u20132 years.<\/li>\n\n\n\n<li><strong>Facial structural changes<\/strong> (nose, mandible, maxilla, sinuses) similar to females but often more pronounced.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>NORMAL PUBERTY Timing of Puberty Hormonal Control Growth Spurt and Body Composition Tanner Stages (General) FEMALE PUBERTY Main Pubertal Events Thelarche (Breast Development) Pubic&hellip;<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[685],"class_list":["post-4422430","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-reproductive-disorders"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422430","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":3,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422430\/revisions"}],"predecessor-version":[{"id":4422434,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422430\/revisions\/4422434"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422430"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422430"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}