The larynx is a tube-like structure found at the entrance of the trachea (windpipe). The lump you can see at the front of your throat, commonly known as the Adam’s apple, is your larynx.

The larynx has three main functions:

• It helps channel oxygen into your trachea when you breathe.
• It acts like a valve, closing off the trachea when you swallow to prevent food or liquid entering your airways. 
• It contains two membranes (the vocal cords) which vibrate as air passes through them, producing the sound of your voice.

Laryngitis causes these membranes to become inflamed. They cannot vibrate properly, which leads to the loss of voice associated with laryngitis.

Laryngitis can indicate any acute inflammation of the Larynx whether this is caused by an infection - often following a cold, cough or sore throat - or by mechanical irritation caused by shouting, smoking or inhaling irritant particles. Dry air causes further irritation, and some kinds of central heating and air conditioning will therefore aggravate the condition. Because the vocal cords he in the larynx, hoarseness or complete loss of voice is one of the complications. Laryngitis following a cold may be aggravated by the fact that air is inhaled through the mouth because the nose is blocked, and so is not warmed, moistened and filtered before it reaches the larynx.

The accepted medical treatment includes steam inhalations, since the vapour eases the breathing and soothes the inflammation. This can be made doubly effective by adding essential oils to the inhalation. The traditional choice is Benzoin, which has been used to treat laryngitis, in the form of Friar's Balsam; but Lavender, Sandalwood or Thyme are also effective.

Laryngitis seldom lasts more than a few days, so any symptoms of hoarseness which persist for longer than this may be due to other, more serious, causes and should be properly investigated.