Understanding the problem

A sore throat is often the result of a viral infection, in which case the sufferer may also complain of other cold- or flu-type symptoms such as a fever, headache, runny nose, aching muscles and tiredness. The patient may also have noticed that they have swollen glands or inflamed tonsils and may find swallowing painful.

Common culprits include the rhinovirus, coronavirus and parainfluenza viruses, which cause colds, but the influenza, adenovirus, herpes simplex and Epstein-Barr viruses are also sometimes responsible. Bacterial infections are a more unusual reason for a sore throat, with Streptococcus being the main cause. 

A sore throat can have a non-infectious cause, but this is rare. Sometimes the reason is obvious – for example, a condition such as hayfever, irritation from smoke or a feeding tube, or the result of chemotherapy or radiotherapy. However, in other patients, the cause is much more obscure – for example, if they unknowingly have a condition such as leukaemia or aplastic anaemia.

Medication may also be at play: certain drugs can cause serious blood disorders (e.g., neutropenia and agranulocytosis, both conditions where there is a deficiency in white blood cells which help fight infection), or cause a problem called Stevens-Johnson syndrome, which presents with a high fever, aching muscles and a rash in the mouth and on the body. 

Patients on such drugs, which include the thyroid medicine carbimazole, the antipsychotic clozapine and the arthritis agent sulfasalazine, should be fully aware of the potential for such issues and know to seek urgent medical help if they experience any symptoms, including a sore throat.