Can I ignore my jury duty letter? Or is that too risky? I really don’t feel comfortable attending.

I can only comment from a UK perspective but I have been called once. I was fortunate to be on a very good jury and it did feel like justice was served. I won't mention the crimes the person did but the verdict reached was fair and considered.

My experience is there is a lot of waiting either to be selected or whilst legal bits were discussed. I'd recommend having some novels to read to pass the time.

If you have real concerns medically I'd speak to your doctor as there are legitimate reasons to not serve.