dysfunctional uterine bleeding (DUB) include:
Vaginal bleeding that occurs more often than
every 21 days or farther apart than 35 days (a normal teen menstrual cycle can
last up to 45 days).
Vaginal bleeding that lasts longer than 7 days (normally lasts 4
to 6 days).
Blood loss of more than
80 mL (3 fl oz) each
menstrual cycle [normally about
30 mL (1 fl oz)]. If you are
passing blood clots and soaking through your usual pads or tampons each hour
for 2 or more hours, your bleeding is considered severe.
Most menstrual blood is lost in the first 3 days of the
period. So excessive blood loss is possible without having
exceptionally long periods.