Hoarseness is a general term which describes abnormal voice changes. The more tightly the vocal folds are held and the smaller the vocal folds, the more rapidly they vibrate.
More rapid vibration makes a higher voice pitch.
Swelling or lumps on the vocal folds prevent them from coming together properly, which makes a change in the voice. There are many causes of hoarseness. Fortunately, most are not serious and tend to go away in a short period of time. The most common causes are acute laryngitis which usually occurs due to swelling from a common cold, upper respiratory tract viral infection, or irritation caused by excessive voice use such as screaming at a sporting event or rock concert. More prolonged hoarseness is usually due to using your voice either too much, too loudly, or improperly over extended periods of time.