Last night I had a panic attack, this isn t my first one and I know in a few days I ll feel back to myself. But I was also diagnosed with cold induced urticaria today and started taking a CVS brand of zyrtec which left me feeling a little out of it, with senses hightened and muscles tense. I also get a pain in the back right of my head sometimes, almost every day, it doesn t last long but it scares me to think it may be a symptom of an underlying problem for my panick attacks and cold urticaria. Please let me know if I should be worried and what it could be because I don t have the money or insurance to keep visiting doctors and emergency rooms. Thank you

Summarized question: What causes cold induced urticaria?