RTIs can affect the airways, such as with bronchitis, or the air sacs at the end of the airways, as in the case of pneumonia. LRTI is a broad terminology which includes acute bronchitis, pneumonia, acute exacerbations of chronic obstructive pulmonary disease/chronic bronchitis (AECB), and acute exacerbation of bronchiectasis. Acute LRTIs (ALRTIs) are one of the common clinical problems in community and hospital settings. Management of community-acquired pneumonia (CAP) and AECB may pose challenges because of the difficulty in differentiating infections caused by typical and atypical microorganisms and rising rates of antimicrobial resistance. Beta-lactam antibiotics, macrolides, and fluoroquinolones are routinely prescribed medicines for the management of ALRTIs.

Macrolide antibiotics are tried and tested, and effective agents for the treatment of LRTIs. Clarithromycin, a macrolide, offers several benefits in the management of ALRTIs.

Risk factors that make a person more likely to develop a lower respiratory tract infection include:

  • A recent cold or flu
  • A weakened immune system
  • Being more than 65 years old
  • Being under five years old
  • Recent surgery.


A diagnosis is made during an exam and after discussing the symptoms the patient has and how long they have been present.

Tests to help diagnose the problem include:

  • Pulse oximetry
  • Chest X-rays to check for pneumonia
  • Blood tests to check for bacteria and viruses
  • Mucus samples to look for bacteria and viruses.

Upper vs lower respiratory tract infections

LRTIs differ from upper respiratory tract infections by the area of the respiratory tract they affect.

While lower respiratory tract infections involve the airways below the larynx, upper respiratory tract infections occur in the structures in the larynx or above.

People who have LRTIs will experience coughing as the primary symptom. Patients with upper respiratory tract infections will feel the symptoms mainly above the neck, such as sneezing, headaches, and sore throats. They may also experience body aches, especially if they have a fever.

Lower respiratory tract infections include:

  • Bronchitis
  • Pneumonia
  • Bronchiolitis
  • TB.

Upper respiratory tract infections include:

  • Common colds
  • Sinus infections
  • Tonsillitis
  • Laryngitis.

Flu infections can affect both the upper and lower respiratory tracts. 


Mahashur A. Management of lower respiratory tract infection in outpatient settings: Focus on clarithromycin. Lung India 2018;35:143-9

Medical News Today. Medically reviewed by Alana Biggers, M.D., MPH — Written by Jenna Fletcher on February 11, 2019. Accessed 26 March 2021.