I was prescribed some antihistamines and over-the-counter decongestants.. is it serious?

Need More Info: It is probably not serious, but you cannot determine the seriousness of a disease just by knowing the recommended medications. I do not usually give my patients decongestants for long term use due to side effects like insomnia, agitation, elevated blood pressure, and heart rate. They are ok for short term use or when you are sick for a few days.