A subarachnoid hemorrhage (bleeding) is an abnormal and very dangerous condition in which blood collects beneath the membrane that covers the brain. This area, called the subarachnoid space, normally contains cerebrospinal fluid (fluid around the brain and spinal cord). The immediate danger due to subarachnoid hemorrhage is ischemia (tissue damage caused by blocked blood flow). These areas of the brain that do not receive enough oxygen can suffer permanent injury, leading to lasting brain damage or death. An individual who survives the initial hemorrhage is at risk for a number of difficulties in the following hours, days, and weeks. The most common problem is increased pressure in the brain.
A computed tomography (CT) scan is used to diagnose a bleed in the head. In addition to monitoring vital signs and intravenous (IV) fluids, treatment may involve mechanical ventilation (breathing machine), and monitoring of the pressures in the head. Medicines for pain, nausea, and vomiting and sedation are administered as needed. Individuals who are awake have the best prognosis. Disabilities may include partial paralysis, weakened or numbed areas of the body, learning or speech difficulties, and vision problems.