When hoarse, the voice may sound breathy, raspy, strained, or there may be changes in volume (loudness) or pitch (how high or low the voice is).
There are many causes of hoarseness. Fortunately, most are not serious and tend to go away in a short period of time. Some common causes of hoarseness are Acute Laryngitis, Vocal Nodules, Gastroesophageal Reflux and damage caused by Smoking. Some less common, but important causes include thyroid problems, neurological disorders, trauma to the voice box, and cancers of the voice box and gullet.
You should seek a specialist opinion on your hoarse voice if it lasts longer than two weeks, if there is pain, if you are coughing up blood, have a lump in your neck, or if the change is very severe and lasts longer than a few days.