what are warfarin side effects?
['Severe bleeding, including heavier than normal menstrual bleeding.', 'Red or brown urine.', 'Black or bloody stool.', 'Severe headache or stomach pain.', 'Joint pain, discomfort or swelling, especially after an injury.', 'Vomiting of blood or material that looks like coffee grounds.', 'Coughing up blood.']