Health Anxiety - anyone got any good ideas of how best to tackle it?

I find using Dr Google can bring up many more possible causes I hadn't thought of and are rare anyway. This can be unhelpful and increase the anxiety. If I do need to look something up online I try to stick to official sites such as NHS.

I think with me the anxiety is largely related to a fear that I might need to visit doctors or hospitals, something which I tend to avoid.

As part of my autism diagnosis I became aware that I experience hypersensitive interoception. That means I am much more aware of my own internal bodily sensations and can become overwhelmed by them. My new found knowledge of my increased awareness means I can reassure myself that the physical sensation is normal and it's just that I am more aware of it. 

I wonder if it is possible that you and your son experience hypersensitive interoception too? When you are much more aware of your body you notice things that most people would not even be aware of. It does not mean that there is anything physically wrong, just that you experience those physical sensations very differently because you are autistic.

The other thing I would say is that stress and anxiety can often find new and surprising ways to manifest in the body. 

This is so very helpful Autonomistic - thank you so much. 
I’m the same - googling symptoms is a disaster for me and I try to avoid that as it will only worry me more. I sometimes ask my husband to check things on my behalf for reassurance. Like you I have a terrible fear of any medical setting. I spent a lot of time in hospital as a child which I think has a large role in that, and unfortunately last year I had a really serious physical health problem and spent weeks in hospital - and that’s made it so much worse. I can’t face medical settings now without very severe anxiety. 

I have never heard of hyper sensitive interoception - that sounds very like myself and my son. We are deeply disconcerted by any physical sensation that feels unusual or ‘wrong’ to us. We ‘feel things too much’ - if that makes sense? I’m ok with cuts and bruises and things like that - it’s other sensations that really bother me. However my son can get really troubled even a really small scratch can be really troubling for him. 

Thank you for telling me about this - I’ll try and find out more about it. I think you may have hit the nail on the head! 

I’m sorry you struggle with this too - it’s not easy is it? Myself and my son need to find a way to bring more rest and peace to our minds and bodies. 

There is a discussion about it on here https://community.autism.org.uk/f/adults-on-the-autistic-spectrum/20092/anyone-with-interoceptive-hypersensitivity and also some further discussion within https://community.autism.org.uk/f/miscellaneous-and-chat/27895/i-feel-like-an-alien

Much of what I have found online is written from the perspective of helping autistic children who experience hyposensitive interoception.

I found an article here which seems to explain hypersensitivity fairly well:

Hypersensitivity to interoception - meaning someone is very sensitive to interoception - can mean someone is overwhelmed by feelings that are a part of the body's day-to-day functioning. This can make sensations difficult to interpret, and can also cause anxiety, stress and/or distraction, as well as discomfort and pain. A common experience reported by many people who are hyper-sensitive to some interoceptive cues is that their own heartbeat can be extremely distracting.

There is a discussion about it on here https://community.autism.org.uk/f/adults-on-the-autistic-spectrum/20092/anyone-with-interoceptive-hypersensitivity and also some further discussion within https://community.autism.org.uk/f/miscellaneous-and-chat/27895/i-feel-like-an-alien

Much of what I have found online is written from the perspective of helping autistic children who experience hyposensitive interoception.

I found an article here which seems to explain hypersensitivity fairly well:

Hypersensitivity to interoception - meaning someone is very sensitive to interoception - can mean someone is overwhelmed by feelings that are a part of the body's day-to-day functioning. This can make sensations difficult to interpret, and can also cause anxiety, stress and/or distraction, as well as discomfort and pain. A common experience reported by many people who are hyper-sensitive to some interoceptive cues is that their own heartbeat can be extremely distracting.