A night of, say, excited yelling at a concert, or maybe speaking too much, or perhaps coughing or being sick, will usually result in “losing your voice.” What’s happening when you find yourself feeling hoarse is the same as when you feel a sore muscle–the overuse of that muscle has caused inflammation and tiredness.
Your vocal cords (also called your larynx) are two flaps of elastic tissue that produce sound by vibrating. When you aren’t using them, they are relaxed and the space between the two cords are open. Alternatively, when you speak or yell, the space between the cords closes as your lungs push air between them, causing vibration and creating sound.
Helping a sore throat after a long night of singing and yelling recover can be as easy as resting your voice and drinking warm water (try it with some honey and lemon!). However, since a sore throat may be caused by a viral or bacterial infection, it is always a good idea to contact your physician, especially if it comes on rather unexpectedly.