Subarachnoid haemorrhage (SAH) is a leakage of blood beneath the arachnoid membrane of the brain, from a major blood vessel. It affects a person suddenly and usually without any prior warning.
SAH causes the sufferer to develop sudden and severe headache, which is often accompanied by nausea, vomiting, neck stiffness and sometimes collapse, seizure and loss of consciousness.
Subarachnoid haemorrhage is commonly a shock to the patient and their family. Many people have anxieties during the illness and recovery periods and lots of questions.
Written by Lesley Foulkes and Sarah Halcrow © 2007 University Hospital Southampton NHS Foundation Trust