A person may lose his or her voice due to a condition called laryngitis, an inflammation of the voice box, according to WebMD. This condition can be temporary or long lasting, and it causes the voice to be hoarse.
The causes of laryngitis include flu, acid reflux, irritation, inhaled steroid drugs and shouting loudly especially during events, according to WebMD. Chronic laryngitis is usually caused by acid reflux. The main symptom is hoarseness, and the voice can also be raspy and deeper than normal. In some situations, a person can lose his or her voice completely. A physical exam is required to identify and treat the underlying cause.