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.
1 Your beard, which is the hair on your cheeks, chin, and neck, may also start to come in.  The pits: As puberty starts, you'll begin growing hair underneath your arms. It will probably be light and soft at first, but will get thicker as you get older.