what are the side effects of low blood platelets?
['Unexpected bruising.', 'Small purple or red spots under the skin, called petechiae.', 'Bleeding from the nose or gums.', 'Heavier-than-usual menstrual periods in women.', 'Black or bloody bowel movements.', 'Red- or pink-colored urine.', 'Bloody vomit.', 'Severe headaches.']