If you’ve ever woken up and found you can’t speak above a whisper, you know the discomfort—and inconvenience—of having laryngitis. A swelling of the vocal cords, laryngitis is usually caused by a viral infection, according to the American Academy of Otolaryngology–Head and Neck Surgery. Swollen vocal cords vibrate differently, leading to hoarseness. Because antibiotics aren’t effective in treating a viral infection, resting your voice is the best medicine. Swollen vocal cords are at risk for serious injury, such as blood in the vocal cords or formation of vocal-cord nodules, polyps or cysts. So be smart: Be quiet!