Subarachnoid Hemorrhage
Overview
Plain-Language Overview
Subarachnoid Hemorrhage is a serious medical condition where bleeding occurs in the space between the brain and the thin tissues covering it. This area is called the subarachnoid space, and it contains cerebrospinal fluid that cushions the brain. When bleeding happens here, it can cause a sudden, severe headache often described as the worst headache ever experienced. This bleeding affects the brain and nervous system, leading to symptoms like neck stiffness, nausea, and sometimes loss of consciousness. The condition can be life-threatening because the blood can increase pressure on the brain and damage brain cells. Immediate medical attention is critical to diagnose and manage the bleeding to prevent complications.
Clinical Definition
Subarachnoid Hemorrhage (SAH) is defined as bleeding into the subarachnoid space of the brain, typically caused by rupture of a cerebral aneurysm or less commonly by trauma or arteriovenous malformations. The hemorrhage leads to sudden release of blood into the cerebrospinal fluid, causing increased intracranial pressure and irritation of the meninges. Clinically, SAH presents with a thunderclap headache, often accompanied by nausea, vomiting, photophobia, and neck stiffness. It is a neurologic emergency due to the risk of rebleeding, vasospasm, and hydrocephalus, which can cause significant morbidity and mortality. Diagnosis and early intervention are crucial to improve outcomes. SAH accounts for a significant proportion of stroke-related deaths and long-term disability.