Adolescence is a transitional stage of human physical and psychological development that generally occurs during the period from puberty to adulthood. Adolescence is usually associated with the teenage years, but its physical, psychological or cultural expressions may begin earlier or end later. Puberty typically begins during preadolescence, particularly in females. Physical growth and cognitive development can extend past the teens. Age provides only a rough marker of adolescence, and scholars have not agreed upon a precise definition. Some definitions start as early as 10 and end as late as 30. The World Health Organization definition officially designates adolescence as the phase of life from ages 10 to 19.