I would like to post this because I discovered an important link in my case. I had many physical symptoms that gave me a lot of anxiety and I obsessively researched about many different diseases in a typical health anxiety way.
when I had tests with a neurologist that implied that there was not a physical disease, I was told that is was all anxiety.
So I thought that my mind was somehow producing these symptoms in some strange way. The symptoms did come less as I worried less about them but did not fully go and resurfaced later when again I was under stress.
It was not till some time later that I made a connection that many of these symptoms were in fact caused by my breathing - hyperventilation which means over-breathing..... (can be over-fast breathing, upper chest breathing, frequent sighing or yawning, taking too big breaths, breathing with tensed up muscles etc.) You may not be aware at all that you are hyperventilating if the hyperventilation is of the chronic type, rather than major acute hyperventilation that may cause a panic attack, fainting etc.
I think most if not all people with anxiety will be hyperventilating chronically to some degree or other.
What happened is that due to stress I started over-breathing, I got some symptoms (muscle twitching and weakness ) I then got disease anxiety and then hyperventilated more and little by little got more and more symptoms in a vicious circle. These symptoms included muscle twitching, tingling, numbness ,a tight band sensation on many parts of my skin in different parts of the body,blurred vision, weird sensations in my mouth, dry mouth, lump in throat, gagging easily, muscle fatigue and aching, joint pains, other weird pains, electric shock feelings, insect crawling sensations, headache, sensitivity to cold , frequent peeing, pins and needles in my back, sunburned skin feeling,chest pain,burning sensations, feeling overwhelmed, irritable, anxious, feeling heat in the body etc, etc, Every time I got a new symptom I would freak out as I did not know at the time what was causing it.
At some point I started practicing some deep breathing exercises and I worked out that I could trigger some of these symptoms quite quickly by changing my breathing - that is how I started to make the link.
I recommend that anyone with anxiety and health anxiety can check their breathing and see if that is triggering any of their symptoms. You can check a lot of information on internet about hyperventilation (in my case I had many more symptoms than appear on many of the hyperventilation symptoms lists) . You can help to retrain your breathing with a respiratory physiotherapist and ask them to help you diagnose if in fact breathing is part of your problem or you can also check out the buteyko technique. Some doctors are knowledgeable about hyperventilation and may refer you to a physiotherapist. Others have very little knowledge about it and may dismiss the subject - but in my case I have seen how much my breathing affected my mind and body, which has made me think that anyone with anxiety issues should pay attention to the breath. In my case just knowing the cause of the physical symptoms was a huge relief - it wasnt a major disease and it wasn't my mind making them - it was my breathing. (I am not saying the mind cannot sometimes create physical symptoms - it may do - I dont know - I am just talking about my own case) .
Also there is a book about hyperventilation by Dinah Bradley which explains a lot how to normalise the breathing. But my advice is not to obsess too much about breathing - dont change it all in a rush but calmly and over time . If your breathing is light , steady and calm you should feel much more grounded and less anxious and better able to deal with whatever is making you anxious or stressed.
I also found EFT was a great help for me dealing with anxiety - at first sometimes my anxiety seemed to get more when I used it but it did finally get much less.
I am not very able to answer individual people's questions about individual symptoms and their cause - I can only say that hyperventilation in my case did make many many physical symptoms. I wish every body the all the best with overcoming anxiety!