Lung auscultation is one of the most important skills in respiratory assessment. Abnormal lung sounds, also called adventitious lung sounds, can indicate underlying pulmonary or cardiac disease and help guide diagnosis and treatment. Recognizing these sounds and understanding their clinical implications is essential for nurses, doctors, respiratory therapists, and medical students.
This article covers:
- What abnormal lung sounds are
- Types of abnormal lung sounds and their descriptions
- Pathophysiology of each sound
- Associated diseases and conditions
- Treatment strategies
- NCLEX and clinical tips
Understanding Abnormal Lung Sounds
Normal lung sounds are vesicular, bronchial, or bronchovesicular. Abnormal lung sounds arise when there is:
- Airway narrowing
- Fluid in the alveoli
- Mucus in the bronchi
- Inflammation of lung tissue or pleura
- Obstruction of airflow
- Abnormal breathing patterns due to neurological or metabolic causes
Healthcare providers use a stethoscope to detect these sounds over specific lung fields, correlating findings with patient symptoms and history.
1. Wheezes (“Whistle”)
Description
- High-pitched, musical, flute-like sound
- Heard mainly during exhalation, but can occur on inhalation
- Caused by narrowed airways from inflammation or bronchoconstriction
Location
- Entire lung field
Pathophysiology
- Airflow through constricted bronchioles generates vibration, producing a wheeze
- Common in diseases with bronchospasm and airway inflammation
Associated Diseases
- Asthma attacks
- Chronic Obstructive Pulmonary Disease (COPD)
Treatment
Asthma management using the AIM approach:- A: Albuterol (bronchodilator)
- I: Ipratropium (anticholinergic)
- M: Methylprednisolone (steroid to reduce inflammation)
2. Stridor (“Serious Squeak”)
Description
- High-pitched, harsh, inspiratory whistle
- Indicates medical emergency – upper airway obstruction
Location
- Throat region
- Heard during inhalation
Pathophysiology
- Narrowing or blockage in the larynx or trachea leads to turbulent airflow
Associated Diseases
- Choking/foreign body obstruction
- Epiglottitis
- Croup (children)
- Post-thyroid surgery airway obstruction (NCLEX Tip: monitor closely after thyroid surgery)
Treatment
- Immediate airway management
- Endotracheal intubation or emergency surgery
3. Crackles (Rales – “Crazy Fluid”)
Description
- Liquid bubbling or crackling sound
- Fine crackles: High-pitched (like rubbing hair between fingers)
- Coarse crackles: Low-pitched (like Velcro being pulled apart)
Location
- Lower lobes, especially basilar areas
Pathophysiology
- Air opens alveoli that were collapsed due to fluid, producing a popping sound
- Associated with inflammation and congestion
Associated Diseases
- Pulmonary edema (“fluid in the lungs”) – often from congestive heart failure (CHF)
- Pneumonia (infection)
Treatment
- Diuretics (e.g., furosemide) for fluid overload
- Antibiotics for infections
4. Rhonchi (“Rumble”)
Description
- Low-pitched rattling or rumbling, similar to snoring
Location
- Bronchi (not alveoli)
Pathophysiology
- Caused by mucus secretions or airway obstruction
Associated Diseases
- Bronchitis
- COPD
- Pneumonia
- Cystic Fibrosis (thick mucus buildup)
Treatment
- Chest physiotherapy and percussion (vibration vest)
- Increased fluid intake to loosen mucus
- Airway clearance techniques
5. Pleural Friction Rub (“Pebbles Friction”)
Description
- Low-pitched, dry rubbing sound (like two rocks grinding)
- Heard during both inhalation and exhalation
Location
- Front side of lungs
Pathophysiology
- Inflammation of the pleura (lining of the lungs) causes the pleural surfaces to rub together
Associated Diseases
- Worsening pneumonia
- Pleuritis (pleurisy)
Treatment
- Turn, Cough, Deep Breathe (TCDB)
- Incentive spirometry
- Antibiotics if infection is present
6. Cheyne-Stokes Breathing (“Death Rattle”)
Description
- Abnormal breathing pattern with periods of increasing and decreasing respiratory rate
- Often followed by apnea (temporary cessation of breathing)
Pathophysiology
- Seen in severe neurological or cardiac conditions
- Apnea leads to increased CO₂ levels, triggering hyperventilation to expel CO₂
Associated Conditions
- End-stage heart failure
- Stroke
- Traumatic brain injury
Treatment
- Intubation and mechanical ventilation in severe cases
Comparison Table – Abnormal Lung Sounds
| Lung Sound | Pitch / Quality | Location | Main Cause | Common Diseases | Treatment |
|---|---|---|---|---|---|
| Wheezes | High-pitched, musical | Entire lung | Bronchoconstriction | Asthma, COPD | Bronchodilators, Steroids |
| Stridor | High-pitched, harsh | Throat | Airway blockage | Croup, Epiglottitis, Choking | Emergency intubation, Surgery |
| Crackles | Bubbling, crackling | Lower lobes | Fluid in alveoli | CHF, Pneumonia | Diuretics, Antibiotics |
| Rhonchi | Low-pitched, rumbling | Bronchi | Mucus obstruction | Bronchitis, COPD, CF | Chest physiotherapy, Hydration |
| Pleural Friction Rub | Dry, rubbing | Front lung | Inflamed pleural surfaces | Pneumonia, Pleuritis | TCDB, Incentive spirometry |
| Cheyne-Stokes | Cyclic breathing/apnea | General | Neurological/metabolic dysfunction | HF, Stroke | Mechanical ventilation |
Clinical and NCLEX Tips
- Stridor is always an emergency – think airway first (ABCs).
- Wheezes = asthma or COPD – treat with bronchodilators first.
- Fine crackles often signal early CHF – diuretics are key.
- Pleural friction rub means pleuritis – antibiotics if infectious.
- Rhonchi can improve after coughing or suctioning, unlike crackles.
Frequently Asked Questions (FAQs)
Q1. Can lung sounds change after treatment?
Yes, effective treatment can eliminate abnormal sounds (e.g., clearing mucus, reducing fluid).
Q2. Are wheezes always asthma?
No. Wheezes can also occur in COPD, allergic reactions, or airway obstruction.
Q3. Is Cheyne-Stokes breathing always fatal?
No, but it often indicates severe underlying disease requiring urgent evaluation.
Q4. How do nurses document lung sounds?
By describing the type, location, timing (inspiration/expiration), and any changes after intervention.
Q5. Can a patient have more than one abnormal lung sound at the same time?
Yes, especially in complex conditions like pneumonia with COPD.
