What are the side effect of an expectorant?

If your taking an expectorant it is for clearing thick mucus out of your lungs and the way you clear it is by coughing. First take a deep breath (as much as you can) and and start a cough, spit in to a tissue (do not swallow what is produced), breath again (get your breath back) and start the process again. Take your time trying to clear your lungs of the mucus by coughing or you can sometimes cause to much pressure in your lungs and can burst small blood vessels causing you to spit red blood (frank blood if this happens more than three times in 24 hours contact medical advice without fail) Take your time and let the expectorant work, if there is no improvement after 48 hours contact your doctor !