Laryngitis (cont.)

The larynx is the voice box that allows us to speak, shout, whisper, and sing. The larynx consists of a cartilage skeleton that houses the vocal cords that are covered by a mucus lining. Muscles inside the larynx adjust the position, shape, and tension of the vocal cords, allowing us to make different sounds from whispering to to singing. Any change in the air flow (which is generated by the lungs exhaling air) across the vocal cords will affect the voice and the quality of the sound.

The larynx is located at the junction of the mouth and trachea and has a flap-like covering called the epiglottis, whose job it is to prevent food and saliva from entering the larynx during swallowing.

Laryngitis (larynx + itis = inflammation) is an inflammation of the voice box, causing a person to lose their voice. The quality of the voice becomes hoarse or gravelly-sounding or even too quiet or soft to hear.

Picture of the larynx and trachea

• Laryngitis is an inflammation of the vocal cords. Most commonly, acute laryngitis is caused by an infection that inflames the vocal cords.
  
  
• Laryngitis may also be caused by voice overuse with excess talking, singing, or shouting.
  
  
• Chronic laryngitis, often described as lasting for more than three weeks, may be caused by prolonged alcohol use, smoking, and excess coughing.
  
  
• Gastroesophageal reflux disease (GERD) may cause laryngeal inflammation and chronic cough, if acid and digestive juices from the stomach reflux up into the esophagus and back of the throat. Sometimes people are aware of the presence of the acid and experience waterbrash, a sour taste in their mouth. Repeat spills of acid onto the vocal cords will cause a chemical irritation and result in inflammation of the vocal cords that hinders appropriate vibration and generation of sound.
  
  
• Chronic irritation of the vocal cords may also cause polyps or nodules to form on the vocal cords, which may affect the ability of the vocal cords to vibrate causing hoarseness.
  
  
• Stroke may also cause vocal cord muscle paralysis and lead to a weak, hoarse voice and swallowing problems.
  
  
• Damage to the muscles or to the nerves that control them may lead to hoarseness. These nerves may be damaged if there has been trauma to the neck or if surgery has been performed and the nerves inadvertently irritated or severed.
  
  
• Tumors in the neck and chest may compress the nerves and cause them to function poorly.
  
  
• Thyroid inflammation and enlargement can also cause irritation of nerves that supply the vocal cord muscles.
  
  
• Not all individuals who have lost their voice have an infection.
  
  
• Diphtheria is rarely a cause of laryngitis-like symptoms because most people are immunized and protected against this infection.

Source: MedicineNet.com
http://www.medicinenet.com/laryngitis/article.htm