{"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 Hair Development Menarche and Ovarian Changes MALE PUBERTY Main Pubertal Events Testicular Development Penile Growth Tanner Stages for Male Genitalia and Pubic Hair Other Male Pubertal Changes<\/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","post-wrapper","thrv_wrapper"],"_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}]}}