Have you ever shouted so much at a game that your voice was different the next day? Even if it hasn’t happened to you, you’ve almost certainly heard someone whose voice has sounded strange at one time or another.

A hoarse voice is caused by irritation of the vocal cords in your throat, called laryngitis (pronounced lair-in-JY-tis). It’s pretty common and can come from a cold or even too much talking or screaming.

Typically when someone is not able to make a sound, a virus has caused swelling in the larynx, which is the part of the throat that produces a person’s voice. Here’s what happens:

Your larynx, or voice box, is covered by two small, stretchy membranes – your vocal cords. When you are not talking, your vocal cords lie open so that air can pass from your mouth to your lungs. But when you speak, the vocal folds come together, and as air pushes through them, they vibrate. The sound from that vibration travels through your throat and mouth, creating your voice.

The reason people’s voices sound different from one another is that the shape of everyone’s vocal cords, throat and mouth is different, creating a unique sound. Typically, bigger vocal cords mean a lower voice.

When someone has laryngitis, though, their vocal cords are swollen, so they don’t vibrate in the normal way. A little swelling makes your voice hoarse. A lot of swelling can make your voice go away completely – that’s called aphonia (ay-FONE-ee-ah).

An adult is far more likely to completely lose his or her voice than a youngster. People usually don’t develop aphonia until becoming teen-agers. Why? That is just one of the mysteries about laryngitis. Doctors also don’t know why some people lose their voices while others don’t.

But anyone who has lost his voice will tell you that it’s a pretty strange feeling.

“It was just really annoying and really frustrating because I knew I was doing the right stuff but nothing was coming out,” Sarah Joseph, 17, said of her last bout with laryngitis. The senior at Hayfield Secondary School in Alexandria, Va., said the first time she ever had a really hoarse voice from a cold was in sixth grade.

If you do wind up losing your voice this winter – either from rooting for the home team or from a cold – doctors recommend resting your voice. That means not talking. It’s like resting your foot if you have a sprained ankle: If you use it, it doesn’t have a chance to heal.

You also should drink plenty of water. And don’t whisper. “Whispering actually puts more strain on the vocal cords than talking in a nice, normal voice,” said Seth Oringer, a doctor specializing in problems with the ear, nose and throat.