Lance Underwood, age 10, of Erie, Penna., for his question:

WHAT CAUSES LARYNGITIS?

Laryngitis is an inflammation of the tissues of the larynx or voice box. It may be caused by various conditions.

Sometimes germs invade the tissues of the larynx and cause them to become inflamed. Doctors believe that laryngitis may also result from the use of irritating materials, such as tobacco and alcohol.

Breathing irritating substances may also cause inflammation.

Improper use of the voice, which puts extra strain on the larynx and vocal cords, may often cause laryngitis.

When the inflammation begins, the tissues of the larynx swell. Soon the patient becomes hoarse. If the condition continues, the person may lose his voice temporarily because the vocal cords become thick and cannot vibrate to produce sound.

Most cases of laryngitis should be treated by a doctor.

The larynx is located between the back of the tongue and the trachea or windpipe. The larynx is sometimes called the voice box because its upper part contains the vocal cords. Every breath of air that passes in and out of the lungs passes through the larynx.