Upper Respiratory Infection
Upper respiratory infection is the most common acute illness seen in primary care, almost always viral, and typically self-limited within about two weeks.
Symptoms
Runny or congested nose, sore throat, cough, sneezing, and mild fatigue are typical. Fever tends to be low-grade or absent in adults.
Causes and risk
Over 200 viruses can cause a URI; close contact, season, and a weakened immune system all raise the odds of catching one.
How it is evaluated
Diagnosis is clinical. Imaging has no role: up to 87% of adults with a simple cold show sinus CT abnormalities that mean nothing, and radiographic imaging can't reliably distinguish viral from bacterial sinusitis (roughly 61% specificity).
Treatment
Symptomatic care is the standard of care. CDC/ACP high-value care guidance and IDSA, AAP, and AAFP guidance all agree antibiotics should not be used for a cold, flu, COVID-19, or laryngitis -- a Cochrane review confirms no benefit and more side effects when they're given anyway. Bacterial sinusitis is only suspected after 10+ days of symptoms, severe symptoms for 3-4 days, or "double-sickening" (initial improvement followed by worsening).
When to seek care
Respiratory distress, abnormal vital signs, altered mental status, or airway-threatening symptoms (drooling, severe throat swelling) need urgent evaluation rather than home management.