What Causes Flu, Laryngitis With A High Heart Rate?

This week I've had some sort of flu which caused me to lose my voice, however I believe to be getting over it. Today I woke up after an 8 hour sleep, took a decongestant and then went back to sleep for another 6 hours. I've noticed that I've had a high heart rate throughout the day. About two hours ago I ate my first full meal of this day, however I still am having a high heart rate. I don't feel completely at ease unless I am laying down. Should I be alarmed for any reason?