I have been diagnosed with Gerd and took Nexium 40 for 3 months with no relief and hives and acne as side effects. Now, I have been having dizzy and lightheaded spells, shortness of breath, with pain from my shoulders down through both of my arms. On the back of an acid reducer otc medication, it says that these symptoms may be a sign of a more serious condition, but I cannot find out what that condition can be. Right now, I am having an anxiety attack and would like some feedback as I am at a loss.