Melena is dark black, tarry feces associated with upper gastrointestinal bleeding. Black color results from hemoglobin alteration by digestive enzymes. Iron supplements and certain medications can cause grayish-black stools
SAH is bleeding into the subarachnoid space surrounding the brain. Characterized by thunderclap headache that develops rapidly. May include vomiting, decreased consciousness, fever, and seizures. About 15% die within 30 days after aneurysm rupture
Carotid artery dissection occurs when blood enters artery wall layers. Can happen spontaneously or after trauma, including sports activities. Incidence is 2.6-2.9 per 100,000 individuals. More common in younger adults under 50
Melena is black, tarry stool containing blood from upper digestive system. Blood needs 100-200ml to turn stool black. Melena is not a disease but a symptom of underlying condition
Premature discontinuation increases thrombotic event risk. Epidural/spinal hematoma risk increases during neuraxial procedures. Monitor patients for neurologic impairment during neuraxial procedures
Immediate medical attention needed for severe stomach pain, bleeding, or confusion. Common side effects include indigestion, dyspepsia, bleeding, and bruising. Rare serious effects include seizures, anaphylaxis, and liver problems