Hoarseness is a general term that describes abnormal voice changes. 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).
The changes in sound are usually due to disorders related to the vocal cords that are the sound producing parts of the voice box (larynx). While breathing, the vocal cords remain apart. When speaking or singing, they come together, and as air leaves the lungs, they vibrate, producing sound. Swelling or lumps on the vocal cords prevent them from coming together properly and changes the way the cords vibrate, which makes a change in the voice, altering quality, volume, and pitch.