Clinical Skills · Assessment of the Thorax, Lungs, Breast, and Lymphatic System
Breath Sounds and Lung Assessment
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In 30 seconds
Lung Auscultation Listening to internal body sounds with a stethoscope Full entry → is the act of listening to air moving through the airways with a stethoscope. It is one piece of a complete respiratory assessment that also includes inspection (rate, rhythm, depth, effort, use of accessory muscles), palpation, and percussion. Auscultation tells the nurse where air is flowing, how easily it is flowing, and whether any added sounds (Adventitious sounds Extra sounds (crackles, wheezes, rhonchi, rubs, stridor) layered on normal breath sounds Full entry →) are present that suggest mucus, narrowing, fluid, or inflammation.
The key skill is not memorizing a list of sound names — it is building a habit of systematic, side-to-side comparison and describing what you hear in objective terms. Breath sounds are categorized by where they are heard, how loud they are, their pitch, and the relative length of inspiration versus expiration. Anything that deviates from the expected pattern for that location is a finding to document and report.
Why this matters
Breath sounds are one of the fastest bedside signals of a changing respiratory condition. Coarse Crackles Discontinuous popping sounds, fine or coarse, often inspiratory Full entry → at the bases may accompany fluid accumulation; wheezes may accompany narrowed airways; absent sounds on one side may accompany a pneumothorax or large effusion. Serial auscultation — listening on every shift or after a treatment — lets the nurse track whether a patient is improving, worsening, or staying the same. These observations feed directly into what you report to the provider and how you prioritize care. A patient who is comfortable but has new wheezing is a different situation from one with Stridor Harsh inspiratory crowing sound from the upper airway Full entry →, and recognizing that difference quickly protects patient safety.
The college version
Core Concepts
Normal breath sounds: what to expect where
Normal breath sounds are named for the area of the lung where they are normally heard:
- Vesicular sounds — soft, low-pitched, heard over most of the peripheral lung fields. Inspiration is longer than expiration, with no pause between them.
- Bronchovesicular sounds — medium pitch and intensity, heard near the mainstem bronchi: between the scapulae posteriorly and at the first and second intercostal spaces anteriorly. Inspiration and expiration are roughly equal.
- Bronchial sounds — loud, high-pitched, hollow, heard over the manubrium and trachea. Expiration is longer than inspiration, with a brief pause between.
- Tracheal sounds — harsh, high-pitched, heard directly over the trachea in the neck.
The pattern to internalize: sounds get softer and lower-pitched as you move from the central airways out to the periphery. Hearing bronchial or bronchovesicular sounds where vesicular sounds belong (for example, over the bases) is abnormal and is worth documenting and reporting.
Auscultation technique
- Use the diaphragm of the stethoscope for breath sounds; warm it in your hand first so the patient isn't startled.
- Place the chest piece directly on the skin — clothing and gowns muffle and distort sounds.
- Ask the patient to breathe through the mouth, slightly deeper than normal, so airflow is audible.
- Use a systematic sequence: posterior chest from apices to bases, then lateral chest, then anterior chest. At each level, listen on the right and then the left so you compare side to side.
- Listen for at least one full respiratory cycle at each site before moving on.
- Remember infection control: clean the stethoscope between patients per facility policy.
Adventitious (added) sounds
Added sounds are extra noises layered on top of the normal breath sounds:
- Crackles (rales) — discontinuous, popping or crackling sounds; fine crackles are soft and high-pitched (like hair rubbed between fingers), coarse crackles are louder and lower-pitched. Often heard on inspiration, frequently at the bases. They suggest air moving through moisture or airways popping open.
- Wheezes — continuous, musical, high-pitched sounds from narrowed airways; classically heard on expiration but can occur on inspiration. Often associated with bronchospasm or secretions.
- Rhonchi Low-pitched snoring/rattling sounds over larger airways Full entry → — continuous, low-pitched, snoring or rattling sounds, often heard over larger airways; may clear or change with coughing.
- Pleural friction rub Grating sound of inflamed pleural surfaces rubbing Full entry → — a dry, grating, creaking sound heard during inspiration and expiration, often over the lateral chest; it is caused by inflamed pleural surfaces rubbing together. It does not clear with coughing.
- Stridor — a harsh, high-pitched, crowing sound heard mainly on inspiration, originating in the upper airway. Stridor is a medical emergency (airway obstruction) and requires immediate reporting.
Diminished or absent breath sounds
Airflow that cannot be heard may mean air is not getting in. Common causes include pleural effusion (fluid around the lung), pneumothorax (air in the pleural space), hyperinflated lungs (as in advanced COPD), obesity, or simply a patient who is breathing too shallowly to produce audible airflow. When sounds are diminished, check the patient's effort, ask for a deeper breath, and consider whether pain or position is limiting breathing before interpreting the finding.
Clinical Scenario: The Post-Op Patient With Shallow Breaths
Mr. Alvarez is a 62-year-old patient on postoperative day 2 after abdominal surgery. He reports that deep breathing "hurts near the incision." The nurse auscultates his posterior lung fields from apices to bases, comparing sides, and hears coarse crackles at both bases that were not present the day before. His rate is slightly elevated and he is splinting.
The nurse does not stop at "crackles present." She considers the context: pain is limiting his depth of breathing, so air is not moving well into the lower lobes. She documents the objective finding ("coarse crackles bilaterally at bases, clears partially with cough"), reminds him to use his incentive spirometer and to splint his incision when coughing (consistent with his care plan and institutional protocols), and reports the change to the provider. Her job is assessment, support, and communication — not deciding the cause or starting treatment.
Common Confusions
| Do Not Confuse | With | Difference |
|---|---|---|
| Crackles | Rhonchi | Crackles are discontinuous pops (like hair rubbed between fingers) that don't clear with cough; rhonchi are low-pitched rattles that often clear or change with coughing |
| Wheezes | Stridor | Wheezes are musical, usually expiratory, from lower airways; stridor is harsh, inspiratory, from the upper airway and is an emergency |
| "Clear to auscultation" | "I heard nothing" | "Clear" means normal breath sounds with no added sounds, not silence — silence over a lung field is abnormal |
| Bronchial sounds over the trachea | Bronchial sounds over the periphery | Expected at the trachea; abnormal over peripheral lung, where vesicular sounds belong |
| Auscultating over a gown | Auscultating on skin | Clothing distorts and muffles sounds; the exam must be on bare skin (with privacy and draping) |
Eli explains
The same idea, in plain words
Explain it like I’m 10
Your lungs are like two balloons inside a cage. When you breathe, air whooshes through tubes into the balloons, and a stethoscope lets you hear that whoosh. In most places the whoosh sounds soft and gentle, but right by the big tubes it sounds louder and harsher — that's normal! If the nurse hears crackling like tiny bubbles, whistling like a squeezed balloon, or a squeaky door sound in the throat, those are clues that something in the lungs needs checking.
Key takeaways
- Compare side to side at every level — symmetry is the most important check; a difference between right and left is more significant than a single odd sound.
- Know where each normal sound belongs: vesicular in the periphery, bronchovesicular near the mainstem bronchi, bronchial over the trachea and manubrium.
- Timing matters: note whether an added sound is inspiratory, expiratory, or both — wheezes are classically expiratory, fine crackles inspiratory.
- Stridor = upper airway emergency — report immediately; do not wait for the next round.
- Rhonchi often change with coughing; crackles and friction rubs do not.
- Adventitious sounds describe findings, not diagnoses — "coarse crackles at the bases" is objective; "pneumonia" is a provider's interpretation.
- Auscultate on bare skin and clean the stethoscope between patients.
Check yourself
6 review questions from the chapter. Try each one, then open the answer.
You hear soft, low-pitched sounds with inspiration longer than expiration over the right lower lobe. What are these sounds, and are they normal for that location?
Show answer
Vesicular breath sounds — they are normal for the peripheral lung fields.
A patient suddenly develops a harsh, high-pitched inspiratory crowing sound. What is this, and what should you do?
Show answer
Stridor — it suggests upper airway obstruction; report immediately as a potential emergency and stay with the patient.
How is a pleural friction rub different from rhonchi?
Show answer
A friction rub is a dry, grating sound (inflamed pleura rubbing) that does not clear with coughing; rhonchi are low-pitched rattles that typically clear or change with coughing.
Why is side-to-side comparison emphasized during lung auscultation?
Show answer
A difference between the right and left sides at the same level is often more significant than any single finding — asymmetry points to a localized problem (e.g., pneumothorax, effusion).
Where would you expect to hear bronchovesicular sounds?
Show answer
Over the mainstem bronchi: between the scapulae posteriorly and near the first/second intercostal spaces anteriorly.
Name two causes of diminished or absent breath sounds.
Show answer
Pleural effusion, pneumothorax, hyperinflation (advanced COPD), obesity, or shallow breathing; also consider patient effort — ask for a deeper breath before interpreting.
Study tools & related lessonsKey vocabulary · Related
Key vocabulary
- Auscultation
- Listening to internal body sounds with a stethoscope
- Vesicular breath sounds
- Soft, low-pitched sounds over peripheral lung; inspiration longer than expiration
- Adventitious sounds
- Extra sounds (crackles, wheezes, rhonchi, rubs, stridor) layered on normal breath sounds
- Crackles
- Discontinuous popping sounds, fine or coarse, often inspiratory
- Wheeze
- Continuous musical sound from narrowed airways, often expiratory
- Rhonchi
- Low-pitched snoring/rattling sounds over larger airways
- Stridor
- Harsh inspiratory crowing sound from the upper airway
- Pleural friction rub
- Grating sound of inflamed pleural surfaces rubbing
Sources & references
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