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.
Quick Answer. The age at which people grow armpit hair varies, but for boys it is often between the ages of nine and 14. Girls typically begin to grow this hair between eight and 13 years of age. Keep Learning.
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.