A respiratory tract infection is an infection that affects the breathing passages. It is commonly divided into upper respiratory tract infection and lower respiratory tract infection.
Upper respiratory tract infections affect the nose, throat and pharynx. Common examples include the common cold, influenza and acute pharyngitis. Lower respiratory tract infections affect the trachea, bronchi and lungs. Common examples include bronchitis and pneumonia.
Most respiratory tract infections are caused by viruses and can spread through respiratory droplets or contact with contaminated surfaces. Many mild infections improve with rest, adequate fluid intake and medications to relieve symptoms within 1 to 2 weeks. However, some infections may worsen or progress to the lower respiratory tract, especially in young children, older adults or people with weaker immune systems.
Patients with respiratory tract infections may experience fever, cough, sore throat, runny nose, nasal congestion, phlegm and general tiredness.
Upper respiratory tract infections usually cause symptoms such as blocked nose, runny nose, sore throat, mild fever and cough. Lower respiratory tract infections may cause more severe symptoms, including persistent or severe cough, thick phlegm, chest pain, chest tightness, wheezing or breathing difficulty.
Warning signs include shortness of breath, difficulty breathing, persistent high fever, chest pain, confusion, unusual drowsiness or bluish lips. If these symptoms occur, patients should wear a mask and seek medical attention promptly.
Diagnosis usually begins with a review of symptoms, medical history and physical examination. The doctor may ask about the duration of fever, cough pattern, sputum colour, breathing difficulty, recent contact history and whether there are any underlying medical conditions.
During the examination, the doctor may check the throat, nose, temperature, oxygen level and listen to the lungs with a stethoscope. If a lower respiratory tract infection or complication is suspected, further tests may be arranged.
These may include viral tests, blood tests, sputum tests or chest X-ray, depending on the patient’s condition. Chest imaging may be useful when pneumonia or other lung involvement is suspected.
Treatment depends on the cause, severity and location of the infection. Many respiratory tract infections are caused by viruses, so antibiotics are usually not required unless a bacterial infection is suspected or confirmed.
For mild cases, treatment may include adequate rest, drinking enough water, fever-reducing medication, cough medicine or other medications to relieve symptoms. Patients should avoid smoking and second-hand smoke, as these may worsen airway irritation.
Good personal hygiene is also important. Patients are advised to wash hands regularly, wear a surgical mask when symptomatic or in crowded places, and reduce close contact with others to lower the risk of transmission.
If symptoms worsen, persist beyond the expected recovery period, or are associated with breathing difficulty, chest pain, persistent high fever, confusion, drowsiness or bluish lips, medical assessment should be sought promptly.
