Okay, so you can divide those sorts of patients into hypertensive urgency and hypertensive emergency, the emergencies are easy because they've got evidence of organ damage. So if they've had a stroke or TIA dissected the aorta, chest pain, coronary artery disease, acute coronary syndrome, these patients need to have their blood pressure controlled quickly. And they need obviously the target organ damage to be limited for those that we call urgencies, your patients scenario headache, unless the headache is off sinister pathologies, such as that you'd see with a subarachnoid for example, but if it's just a straightforward headache, and they've got hypertension, two things you have to bear in mind, one is the headache may be driving the blood pressure. The second is the blood pressure may be driving the headache, but either way, there's no great urgency about lowering that individual's blood pressure. Most of these patients, when they call me up, I would just say, give the patient some analgesia for the headache, send the patient home, and either the GP consorted out or I will pick them up in my outpatient service. But there is no need to do anything other than reassure the patient and discharge them, they can be seen and managed at our leisure, we don't have to give them anything acute. I mean, if people are worried if the systolic is consistently above 180, or 200, you can start a therapy programme, they won't come to any harm. And depending on the age and the ethnicity of the patient, the selection of your drug will be made for you. But there's no urgency about controlling the blood pressure. And in fact, you can do more harm than good. If you screw the blood pressure down from say, 200 to 140. In 10 minutes, you could cause a stroke. So you don't want to do that.