Could you please tell me what a sub arachnoid haemorrhage and a subdural haemorrhage is?

Location of bleed: SAH is on the surface of the brain and spreads like a thin film, often associated with headache, severe.. SDH is an actual clot forming under the protective layer of the brain, the dura. It expands and pushes on the brain and can result in death in some instances if not treated surgically. Not all require surgery however, depends on neuro symptoms.