Laryngitis - Causes of laryngitis

Laryngitis occurs when the larynx (voice box) becomes irritated and swollen. It's mostly caused by an infection or damage to the larynx.

Infection

Viral infections such as the common cold and flu are the most common type of infection associated with acute laryngitis.

Rarer types of infection include:

bacterial infections, such as diphtheria
fungal infections, such as thrush (candidiasis) or aspergillosis

People with weakened immune systems, due to conditions such as HIV or as a result of chemotherapy or steroid medication, are thought to be most at risk from fungal laryngitis.

Laryngitis caused by a viral, bacterial or fungal infection is known as infectious laryngitis.

Damage to the larynx

Laryngitis is also often caused by straining your voice, such as speaking or singing for long periods or shouting and singing loudly.

Straining your voice can cause your vocal cords to vibrate at a faster rate than they should. This excessive vibration can damage the surface of your vocal cords, causing them to become inflamed.

Laryngitis caused by damage to the larynx is known as mechanical laryngitis.

Less common causes of mechanical laryngitis include:

direct trauma to the larynx - such as a blow to your throat, an accident or a sports injury
prolonged coughing
persistent and frequent clearing of your throat

Other causes

As well as infection and damage to the larynx, laryngitis can also be caused by:

smoking and alcohol misuse, which can dry out and irritate your larynx
gastro-oesophageal reflux disease (GORD) - when stomach acid leaks out of the stomach and up into the throat, where it can irritate your larynx
allergic reactions to substances such as dust, fumes, chemicals and toxins

These causes are most often associated with long-term (chronic) laryngitis.

Acute: Acute means occurring suddenly or over a short period of time.
Antibiotics: Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. Examples of antibiotics include amoxicillin, streptomycin and erythromycin.
Bacteria: Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and others are good for you.
Benign: Benign refers to a condition that should not become life-threatening. In relation to tumours, benign means not cancerous.
Chronic: Chronic usually means a condition that continues for a long time or keeps coming back.
Cyst: A cyst is a fluid-filled sac or cavity in the body.
Inflammation: Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
Shock: Shock is a short-term state of body weakness that usually happens after an accident or injury. It is caused when there is an insufficient supply of oxygen.
Stomach: The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.