Excessive use of the voice
When you hear football fans bellowing as their team scores a goal, or fans at a rock concert singing or shouting alongside the performers, the chances are they are going to know the cause of their sore throat the next day.
Straining your voice in this way, even if you are just talking more than usual, is similar in effect to straining a muscle during a sporting injury. The vocal cords in your throat will be inflamed and damaged, and although this may be sore for a day or two, the damage and soreness is usually temporary.
Your throat consists of delicate structures which can be easily damaged in ways aside from shouting and screaming.
Swallowing something sharp or hard, such as a fish bone or a large piece of crisp, can cause a scratch in your throat. The piece of food could also lodge in your throat, so that every time you swallow, symptoms are aggravated.
This is one of the reasons why it is so important to chew your food properly before you swallow. Apart from eliminating one cause of indigestion, this minimises the chances of you injuring yourself when you eat.
Allergies and Irritants
There is a host of allergies and irritants which can trigger a sore throat, ranging from hayfever to passive smoking.
When you have an allergic reaction your body reacts to the allergen by triggering an inflammatory response, causing tissues to swell. Your body clears this congestion by allowing excess mucus to drip down the back of your throat. This can be uncomfortable and can cause you to cough or swallow more often than normal, irritating your throat.
Gastro-oesophageal acid reflux is a common symptom of indigestion which can cause a sore throat. This arises when the strong digestive acids in your stomach escape up the oesophagus and breaks down its mucus lining. If the acid comes into contact with the cells which line your oesophagus or throat, this can be painful.
Passive smoking and other atmospheric pollutants are also causes of a sore throat. Your throat is lined by a thin layer of mucus and this traps any particles in the air when you breathe in, including pollutants. These pollutants can irritate your throat and cause it to become sore.
Viruses and sore throats
Viruses are the most common cause of a sore throat – particularly cold and flu viruses which start their infection by targeting tissues of the pharynx.
This means you will be affected by a sore throat at some point during the common cold or flu, although this can disappear after a couple of days, even when other symptoms persist.
Bacterial sore throats
It is often difficult to tell whether your sore throat is caused by a virus or bacteria by the symptoms alone, particularly if you pick up a bacterial infection at the end of a cold when your immune system is weaker.
However, some bacterial infections such as those caused by Streptococcus pyogenes can give rise to severe symptoms (known as a Strep throat). Another example is infection by Bordetalla pertussis, the cause of whooping cough.
These infections normally give rise to a persistent sore throat. You will need to go to your doctor to have these conditions diagnosed and treated.
Medical conditions and medication
Certain medical conditions, such as HIV or AIDS, can weaken your immune system. This means that you are more likely to be affected by infections. For example, if you pick up a cold or flu, symptoms, including a sore throat, are likely to be more severe than they normally would be.
Some classes of medication including drugs for rheumatoid arthritis, anti-histamines or anti-depressants can cause a sore throat. These dry out the mucus membranes of the mouth and throat making it more painful to swallow.