Hi, It is not that likely that tonight s headache is due to a ruptured aneurysm. When there is bleeding from an aneurysm the headache is very much severed with a very abrupt onset, patients describe it as the worst headache of their life, often called thunderclap headache. So looks unlikely for him to go to bed with that type of a headache. That being said given his history if a headache persists the next day you should check with his doctor. It s hard to assess whether his prior history means there is an increased risk as you are not very clear what was done on that ruptured aneurysm, whether he had any procedure done like clipping or coiling in order to secure that an aneurysm doesn t bleed again, if he had such a procedure whether follow-up imaging showed an aneurysm to be secure. Without such info, it s hard to assess the risk of rebleeding. Hope I have answered your query. Let me know if I can assist you further.