Absolutely anxiety can cause physical issues! I also have asthma, and I used to always have asthma attacks when I got upset. This is not happening frequently anymore, but a few weeks ago when I had a panic attack, my whole body broke out in hives that lasted for a whole week. I have had many illnesses due to anxiety...anxiety can lower the effectiveness of the immune system. I wish that the medical profession would understand that the mind and the body are not separate. They could help us a lot more if they did.