Signs and Symptoms of Bronchitis
In bronchitis, the irritation to the bronchi and bronchioles triggers the excessive secretion of mucus (hypersecretion). Coupled with the swelling of the wall due to inflammation, the mucus narrows the airway. While a cough is always present, it is not uncommon for other symptoms to be absent in bronchitis.
The main symptom of bronchitis, whether acute or chronic, is a productive cough. This is commonly referred to as a ‘wet cough’. It is episodic and often results in the coughing up of mucus (sputum).
Irritation of the bronchial lining and mucus accumulation within the bronchial tree triggers the cough reflex which aims to expel the irritant and mucus. The mucus expectorated during coughing (sputum) may be clear, yellow, green or brown in color. Brown sputum is usually indicative of an infection. Persistent coughing may cause further inflammation and abrasion of the bronchi, bronchioles, trachea, larynx and/or pharynx thereby causing slight bleeding which is evident as blood-tinged sputum.
In acute bronchitis which is often caused by viral respiratory tract infections, the cough may extend for up to 3 weeks despite the infection having resolved. However, in most cases, it resolves within 10 days. A secondary bacterial infection may also set in during or after the viral infection, especially among immunocompromised patients and cigarette smokers.
In chronic bronchitis, the productive cough lasts for over 3 weeks and recurs for 2 consecutive years or more. It is commonly referred to as a smoker’s cough since cigarette smoking is one of the major causes of chronic bronchitis. The loss of cilia in the respiratory tract epithelium hampers the expulsion of mucus from the traceobronchial tree. Mucus accumulation within the lower respiratory tract may result in rhonchi or crackles as well sometimes changing the typical sound of the cough to a more deep and ‘chesty’ cough.
Bronchitis Short of Breath
Another common symptom of bronchitis is shortness of breath (dyspnea). Ventilation may be adequate but due to the narrowing of the airway, the sensation of shortness of breath is commonly present.
This is a result of mucus secretion and bronchial wall swelling causing narrowing of the airway. In addition, inflammation in the distal parts of the respiratory tract may slightly affect gas exchange. This is further complicated if the mucus is not expectorated efficiently, as is the case with chronic bronchitis, and accumulates lower down the tract or within the lung itself.
Pallor or cyanosis (white to blue discoloration of the skin) due to poor gas perfusion rarely occurs in a case of bronchitis alone and may be an indication of other underlying cardiopulmonary disorders.
Bronchitis Breathing Sounds
The narrowing of the airway often results in a wheeze and other abnormal breathing sounds. This is more pronounced if there is concomitant bronchospasm as is often seen in children with immune mediated hypersensitivity (allergy).
Apart from a wheeze and rhonchi, inflammation higher up the respiratory tract may also cause stridor while mucus accumulation in the lungs may cause crackles.
Asthma should always be excluded in prominent wheezing in children, especially if the onset may have been related to the exposure of known inhaled allergens and irritants, rather than just an infection.
Other Bronchitis Symptoms
Many of the accompanying signs and symptoms may be a result of the respiratory tract infection and not of bronchitis itself. This includes :
- Sore throat
- Runny nose (rhinorrhea) or nasal congestion
- Fatigue, although this may be prominent if the bronchitis is significantly affecting oxygenation
- Muscle aches and pains