My mother has been taken to hospital twice now this was within three days. she has been getting headaches and say's it feel's like getting hit with a sledge hammer on the back of the head she also is sick & can't stand the light, when taken into hospital they gave her a morphine injection & a jab to stop her being sick this seem's to ease the pain, but after keeping her over night they let her out , but she's not that long home when it all start's again she can't bare these haedache's, She has had a CT scan done the other day when she was in the hospital & it came back clear, they wanted to do a lumber puncture but she is on warfarin & they don't want to cause any damage to the heart valves(two steel valves) as one of them is leaking so they changed there mind's. so we're still not any further forward as to what is causing these headaches, they think it might be thunderbolt headaches but we've never heard of this can you help !