I am not sure how I missed this one, having been ill with ME/CFS for over 10 years, and I know there has been a board on here, but somehow I didn't think it applied to me! Anyway, the penny finally dropped earlier this week when I was reviewing my chronic stomach pain that the 'experts' like to call Non Ulcer Dyspepsia which has been going on for years. Before all that I had gastritis some 14 years ago, and before all that going back to when I was 20ish (I am now 64), I had diarrhoea predominant IBS for some years. Maybe all connected I now think...... Having had no help from the NHS other than the offer of medications I didn't want to take for fear of worse side effects, I decided to just alter my diet some 5 or 6 years ago, and cut anything out that triggered the awful pain, that would come on, and increased in intensity and length over the years - would go on for days before calming down. The penny dropped this week, after a calm time, when I realised that chocolate which triggered a really bad stomach pain spell, is high in histamine. A private Dr had offered me a histamine test some 4 years ago, but I was running out of money, and it was expensive, so I turned it down (by then I had spent hundreds with him on various other tests). So, now I look at my other symptoms and can see the connections to the histamine issue - maybe the whole ME/CFS diagnosis......sore throats for years not resolving, nasal soreness, both of which I thought were viruses (Oil of Oregano helps but now I see it is an antihistamine!), migraine aura that has worsened in frequency, fatigue of course, and the awful stomach pain that has floored me at times, and this year worsening allergic rhinitis, especially following some eye drops I needed following an eye operation. Never all the symptoms at the same time, but moving around. So, I hope it is Histamine Intolerance which I can control better and I am already on that case with my diet now better understood - nearly all the foods I had chosen were low histamine, but I can fine tune it now I know more. But how would one know if you have MCAS? If I had ignored the worsening signs of the symptoms I have, would it turn into MCAS? Or do I have it already in a mild form? I plan to work my way through this thread now I understand a bit more about the histamine issue and see what I can see here too of course!