Hi all. Can anyone shed any light on this or have similar symptoms? Every so often (becoming more regular - more like weekly) I wake up with a banging headache, along with nausea and a general feeling of shakiness/weakness and brain fog. I feel a bit as though I have been beaten up in the night or at least doing some sort of intense exercise. All my muscles ache, especially back, neck etc. I have a feeling I might be tensing up as I sleep, causing a tension headache, but would that also cause the nausea? Although it is not every day, when it does happen, it is becoming worse and more debilitating. Today for example, fortunately I was working at home - but if not, there is no way I could have made it into work this morning. The rest of the time I'm fine! Reasonably slim, pretty fit, relatively good diet, etc. Blood pressure more or less OK (getting higher though, having been very low most of my life). I'm 50 and already on HRT. What on earth is it and what can I do? No particular stressors other than the normal, work, kids etc. Thanks for any thoughts in advance!