Physiologic Growth and Development During Adolescence

1. David S. Rosen, MD, MPH* 1. *Editorial Board After completing this article, readers should be able to: 1. Recognize the inherent variability in puberty. 2. Describe the usual sequence of pubertal development in both boys and girls. 3. Describe the pattern of linear growth during puberty. 4. Identify pubertal abnormalities that require further evaluation. Adolescence is a complex and dynamic process characterized by simultaneous but asynchronous development within several development streams. These streams include physical development (puberty), cognitive and psychological development, and social development. Although puberty is only one component of adolescent development, it generally is considered to define the onset of adolescence and certainly is the most visible and tangible of all of the developmental changes occurring during this period. This article reviews the physiologic changes associated with normal puberty. Other developmental aspects are not considered here, and the many abnormalities of puberty that sometimes can occur are not discussed in detail. One of the hallmarks of puberty is its variability. The onset, timing, tempo, and magnitude of pubertal changes are influenced significantly by genetic factors as well as by general health and nutritional, environmental, and socioeconomic factors. The timing of pubertal milestones approximates a normal distribution. Studies correlating the timing of puberty between mothers and children or between twins support a strong genetic influence that has been estimated to account for 50% to 80% of the variance in the timing of pubertal onset. Racial and ethnic variations also are seen. For example, the onset of puberty occurs somewhat earlier in African-American children than it does in Caucasian children. The age of puberty and menarche has declined steadily over the past several generations, attributed to improvements in overall health and nutrition. Several large investigations have documented this secular trend, and it now generally is agreed that puberty often begins at younger ages than are reported in older texts. As a corollary, …