A new study has begun collecting information on patients that present to the Emergency Department with non-traumatic, acute headaches that have maximal onset within 1 hour. Acute headaches account for between 1 and 2 % of all Emergency Department attendances, a significant proportion of which will have a serious pathology such as a subarachnoid haemorrhage (SAH). It has been suggested in literature that CT imaging is able to exclude SAHs if performed within 6 hours for patients presenting with an acute, severe headache. However, this has not yet been validated in UK populations. If you are a clinician with a patient that has a non-traumatic, acute headache that is over the age of 18 please consider talking to them about the SHED study. The study is data collection only and uses an opt-out model, you do not need to consent a patient in order for them to be included. We do, however, ask that you complete the inclusion checklist, copies of which are at the EMERGE research desk in the Emergency Department. Publication date 15 Nov, 2021