Upper respiratory tract infection in the context of "Sinusitis"

Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI or LRTI). Lower respiratory infections, such as pneumonia, tend to be far more severe than upper respiratory infections, such as the common cold.

Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days, but can be longer depending on cause. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.

Most cases are caused by a viral infection. Strep throat, a bacterial infection, is the cause in about 25% of children and 10% of adults. Uncommon causes include other bacteria such as gonococcus, fungi, irritants such as smoke, allergies, and gastroesophageal reflux disease. Specific testing is not recommended in people who have clear symptoms of a viral infection, such as a cold. Otherwise, a rapid antigen detection test or throat swab is recommended. PCR testing has become common as it is as good as taking a throat swab but gives a faster result. Other conditions that can produce similar symptoms include epiglottitis, thyroiditis, retropharyngeal abscess, and occasionally heart disease.