Diseases concerning the throat
When your voice is „leaving“ you, when you can´t swollow properly or you are hoarse, you should see an ENT Doctor. With an endoscope he can check (without pain) the situation of the larynx (throat). This is very important in people who have pain and / or can´t swollow: there could be an edema which needs treatment immediately, because this is the way to your lungs and the possibility to breath!!
If anyone should be hoarse for some weeks and is a smoker, he should have a proper examination of his larynx: cancer e.g. of the vocals or cancer e.g. of the lungs, which paralizes the vocals (and then could cause hoarseness)