Also, Doppler can detect abnormal blood flow within the heart, which can indicate a problem with one or more of the heart's four valves. Color Doppler. Color Doppler is an enhanced form of Doppler echocardiography. With color Doppler, different colors are used to designate the direction of blood flow.
(I got armpit hair around 11 1/2 but everyone is different) From around age 13-16 but it can still happen earlier or later (maybe even 12 and 19) got mine just before i turned 14. Brent Lyday.
Average Age Of Growth Spurts In Boys. The average age at which puberty begins in boys is 11 to 12 years. The end of puberty is not clearly delineated and may vary with the physical, emotional, mental, social and cultural criteria to define an adult boy. However, it usually gets complete at around the age of 17 to 18.