Abnormal breath sounds are usually indicators of problems in the lungs or airways. The most common causes of abnormal breath sounds are:. Go to the emergency room or call local emergency services if breathing difficulty comes on suddenly, is severe, or if someone stops breathing.
Cyanosis , a bluish color of skin and mucous membranes due to lack of oxygen, can occur along with abnormal breath sounds. Cyanosis involving the lips or the face is also a medical emergency. Tell your doctor when you noticed the abnormal sounds and what you were doing before you heard them. Be sure to mention any other symptoms you may be experiencing. These tests can include:. A sputum culture is a test for detecting foreign organisms in the mucus of the lungs, such as abnormal bacteria or fungi.
For this test, your doctor asks you to cough and then collects the sputum you cough up. This sample is then sent to a lab for analysis. Treatment options for abnormal breath sounds depend on your diagnosis. Your doctor takes the cause and the severity of your symptoms into consideration when recommending a treatment.
Medications are often prescribed to clear up infections or to open the airways. Squawks is a term used to describe very short wheezes that usually occur late during inspiration. They may be seen with conditions such as pneumonia, lung fibrosis , or bronchiolitis obliterans. Wheezing may be diffuse and generalized, such as with asthma, or occur focally in one region due to obstruction by a foreign body or tumor.
Stridor refers to a high-pitched sound with a musical quality that is heard mostly with inspiration; it is typically loudest over the neck. It is a continuous sound the occurs when there is a blockage in the upper airways. Obstruction in the upper airways is less common than in the lower airways and may be due to:. With pertussis whooping cough , a high-pitched "whoop" sound may be heard after coughing. Rhonchi, in contrast to wheezes, are described as low-pitched clunky or rattling sounds, though they sometimes resemble snoring.
They often clear with coughing and are usually caused by an obstruction or build-up of mucus in the large airways. Rales or crackles are also referred to as crepitation and are often intermittent sounds that are most pronounced with inspiration. The sounds have been described as clunky, rattling, crackling, clinking, or popping, and they occur when the smaller airways open suddenly during inspiration. Crackles can be further defined as moist or dry, fine or coarse, with fine crackles thought to be related more to small airway disease and coarse crackles seen with large airway conditions.
These sounds are often related to the build-up of fluid in the alveoli , the tiniest airways of the lungs. A pleural rub is a gritty sound that has been likened to the sound of walking on fresh snow or sitting down on a leather couch. Unlike rales, the sound does not clear with coughing. A pleural rub may occur during both inspiration and expiration.
Conditions that cause inflammation of the membranes lining the lungs pleura can result in a rub, such as:. In addition to auscultation, there are several other components to a thorough lung examination. The sounds your healthcare provider hears are considered alongside the information gleaned during the rest of your assessment, as well as the results of any tests done, to determine if your breathing is normal or to help reach a diagnosis.
Visualization of the chest is an important part of a lung exam along with listening and palpating touching. Healthcare providers note a number of factors during inspection:. Palpation or feeling the chest is also important. Findings may include:. Percussion or tapping on the chest is the final aspect of a comprehensive lung exam. Laying one finger on the chest and tapping that finger with another usually results in a resonant sound. Abnormal findings may include:. There are a number of other physical signs that may give clues to lung disease, and a lung exam should be performed along with a general physical exam when time allows.
There are other factors that could affect breathing or findings during the lung exam, including obesity or scoliosis. These, too, will be noted. Depending on the lung exam, as well as symptoms and risk factors, lab and imaging tests may be recommended. Auscultation can be an easily overlooked tool with the technology available to healthcare providers today.
However, it is an important part of a physical examination. While inexpensive and easy to perform, it provides a wealth of information that can help in diagnosing lung diseases and other conditions. Taking the time to ask your healthcare providers what they are listening for, and what they hear on your exam, is a good start toward being your own advocate in your health care.
Looking to avoid getting the flu? Our free guide has everything you need to stay healthy this season. Bohadana et al. In areas where there is no pulmonary function laboratory, BSI can be of great use. Inspiration is represented by upstroke and expiration by down stroke.
Length of upstroke and down stroke indicates length of inspiration and expiration, respectively. Thickness indicates intensity of the sound. Pitch of inspiration is measured by the angle it makes with the perpendicular line.
It is normally heard anteriorly over the manubrium and posteriorly between the C7 and T3 vertebrae. Bronchial breath sounds contain much higher frequency components than normal breath sounds due to alteration of the low pass filtering function of the alveoli, as occurs in consolidation.
Expiratory phase is longer than inspiratory phase with the I:E changing from normal to There is distinct pause between inspiration and expiration due to absent alveolar phase. Check for whispering pectoriloquy is absolutely essential in case of doubt about the presence of bronchial breathing as whispering pectoriloquy is always present along with bronchial breath sound. It is a high pitch, bronchial breath sound. It can be seen in the following conditions:. In distal collapse, if collapse segment is in contact with chest wall and bronchus is patent, bronchial breathing may be present.
It is a low pitch bronchial breath sound with high pitch overtones. It has a metallic character. Amphoric breathing can be produced by blowing over the mouth of an empty glass or clay jar. Greek word amphoreus means jar so it is called amphoric breathing. It occurs in the presence of a superficial large cavity not less than cm in diameter with patent bronchi and open pneumothorax. Smooth wall is also a requirement as it is capable of reflecting sound.
High pitch overtones occur because of strong resonance of sound waves within cavity wall or pleural cavity. Presence of fungal ball or fluid within cavity causes disappearance of amphoric breath sound. Amphoric breathing is also not heard if normal alveoli are present, so presence of amphoric breathing means alveolar destruction. It is a low pitch bronchial breath sound heard over superficial large cavity with patent bronchus, abscess, and bronchiectatic cavity with patent bronchi.
It is harsh, very loud, and high pitched sound heard over the trachea. Typical frequency of tracheal breath sound varies from to 1, Hz, with a drop in power above a cutoff frequency of approximately Hz sharply. Frequency range of tracheal sound is much wider than normal lung sound with frequencies ranging from to 5, Hz, with a sharp drop in energy at a frequency of approximately Hz.
First, it has hollow tubular quality so it is a good model for studying bronchial breath sound. Second, tracheal breath sound can be helpful in detecting upper airway obstruction UAO. It becomes noisy in case of UAO. Spectral analysis of tracheal sound is also helpful in this regard. Normally there is a small spectral peak observed at 1 kHz.
Patients with significant tracheal stenosis; however, demonstrate an increase in the peak spectral power at 1 kHz and there is also an increase in the mean spectral power from to 1, Hz.
It is intermediate between bronchial and vescicular breathing. It has intermediate intensity and pitch with same duration of inspiratory and expiratory phase. It is normally heard anteriorly over 1 st and 2 nd intercostal spaces and between scapulae posteriorly.
It is abnormal in other locations. Occasionally, vesicular breathing becomes interrupted during inspiration and is called cogwheel breathing, for example, bronchial obstruction by mediastinal lymph nodes or aortic aneurysm or nervousness and fatigue. Breath sound produced in the central airways can traverse both upwards and downwards.
Though they originate from the same sites, they are different acoustically as frequencies above Hz are filtered off in case of sound heard at chest wall by the alveolar air and chest wall. Breath sounds heard at mouth contain frequency distributed widely from to 2, Hz like normal white noise. However, this sign is less frequently used in modern day.
One reason may be that stridor and wheeze are often confused with noisy breathing. Noisy inspiration is common in chronic bronchitis and asthma, but not in patients with emphysema. Noisy breath sound at mouth is due to increased turbulence caused by surface irregularities in the airways, abrupt changes in the direction of flow, or narrowing of the airways resulting in more rapid flow.
In emphysema, sound at mouth is either not audible or audible slightly above normal. Emphysema patients develop airflow obstruction due to loss of elastic recoil of the lung leading to small airway obstruction, and dynamic compression of the central airways. However, in chronic bronchitis and asthma patients, the caliber of the central airways remains normal during inspiration.
Voice sounds are produced by the larynx. They are produced when puffs of air pass through the vocal folds, producing its vibration. Therefore; unlike breath sounds and adventitious sounds, they are not produced in the lungs.
Voice sounds are subsequently modulated by filter function of the supralaryngeal airway. Voice sounds consist of a fundamental frequency and several overtones called together harmonics.
Fundamental frequency is determined by the number of times the vocal folds vibrate in 1 s, and is measured in hertz. Fundamental frequency is the lowest resonant frequency of vibrating cords. Overtones are multiples of fundamental frequency.
Vowel sound contains a mixture of high and low frequency overtones called formants. Normally, in healthy person, due to filtering effect of air-filled lungs, voice sounds are unintelligible as higher frequencies are lost. However, when air in the lungs is replaced by fluid or solid substances or the lungs undergo atelectasis, voice sounds are better transmitted and become well-distinct.
There are three types of transmitted voice sounds: Whispered pectoriloquy, bronchophony, and egophony. Bronchophony is present if sounds can be heard with an increase in intensity and clarity. During whispering, vocal folds do not vibrate, but are held close together. This produces a turbulent flow of air resulting in a windy sound characteristic of whispering. Normally, words are heard faintly.
However, in cases of consolidation, the whispered sounds will be heard clearly and distinctly. It is present in cases of consolidation or pleural effusion. In pleural effusion; egophony is present just above the area of dullness. Sound E consists of high frequency of 2,, Hz and low frequency of Hz. In sound A, the low frequency is higher than E and reaches up to Hz. Unlike normal lung, consolidated lungs transmit both higher and lower frequency well, but no significant transmission occurred above a frequency of 1, Hz.
Therefore, consolidated lungs can not transmit the higher frequency of e, but can transmit the lower frequency of A well, so Ee becomes A. Patients of large pleural effusions have upward displacement and compression of the lung above the level of effusion. Fluid in the pleural space compresses the overlying lung parenchyma, making it more solid than normal. It results in modification of the acoustic properties of the lung, which becomes a better transmitter of high frequency sound and causes appearance of egophony.
Animal study has shown that pleural effusion altered the transmission of sound from vocal cords to chest wall. Pleural fluid decreases the transmission of sound of wavelength between and Hz fundamental frequency of speech and increases transmissibility of higher frequencies. Adventitious sounds are additional respiratory sounds superimposed on normal breath sounds.
As early as , Robertson and Coope[ 22 ] proposed a simplified classification of adventitious lung sounds into two main categories; continuous and interrupted sounds. Continuous sounds were further classified into high- and low-pitched wheezes, and the interrupted sounds were divided into three categories: Coarse, medium, and fine crackles. International Lung Sound Association in further simplified the terminology: Discontinuous sound into fine and coarse crackles and continuous sound into wheeze and rhonchi.
Continuous adventitious sound lasts more than ms. The American Thoracic Society ATS Committee on pulmonary nomenclature defines wheezes as high-pitched continuous sounds with a dominant frequency of Hz or more, and rhonchi as low-pitched continuous musical sounds with a dominant frequency of about Hz or less. Rhonchi have a snoring quality as thepitch is typically near Hz. Severe obstruction of the intrathoracic lower airway or upper airways obstruction can be associated with inspiratory wheezes.
Asthma and chronic obstructive pulmonary diseases COPD patients develop generalized airway obstruction; therefore, wheezes are heard all over the chest. Localized airway obstruction by a foreign body, mucous plug, or tumor produces focal wheezing. Wheezing is a nonspecific finding and may even be detected in a healthy person towards the end of expiration after forceful expirations. Pathological wheezing can be produced with a gentle expiratory maneuver.
Wheezes may even be absent in asthma patients with severe airway obstruction. The production of wheezing sounds requires a certain degree of airflow. In acute severe asthma, respiratory flows become so low that they are unable to provide the energy necessary to generate wheezes or any sounds.
Therefore, there appearance of wheeze after a period of silent chest is a sign of improvement. The important prerequisite for the production of wheeze is airflow limitation,[ 28 ] but airflow limitation can occur in the absence of wheezes. Forgacs, in , proposed that wheezes are generated by the oscillations of the bronchial walls initiated by airflow, and the pitch of the wheeze depends on the mechanical properties of the bronchial walls.
The comparison with atoy trumpet reveals that vortices shedding near sharp edges are responsible for the bronchial wall vibration. The pitch of the trumpet is determined by the mass and elasticity of the reed. Similarly, the pitch of the wheeze depends on the mass and elasticity of the airway walls and the flow velocity, but not on the length or the size of the airway.
Pitch does not depend eitheron the density of the flowing gas as there is no noticeable change in the character of wheezing when the patient is exposed to a helium-oxygen mixture. Gavriely et al. The fluttering begins when the airflow velocity reaches a critical value, called flutter velocity.
Although the frequency of flutter increases with the narrow channel, a small airway is usually not the site of wheeze production as the speed of airflow is too low to reach the critical flutter velocity required for the production of wheeze. This principal states that when air flows through a narrow tube at high velocity, it causes a fall in pressure within the airway.
Low intra-airway pressure causes a collapse of the airway. As the collapse worsens, it increases obstruction and intra-airway pressure. The increased intra-airway pressure decreases the obstruction by pushing the airway wall outside, and the fluttering cycle starts anew. Monophonic wheezing consists of a single musical notes starting and ending at different times. A local pathology-like bronchial obstruction by tumor, bronchostenosis by inflammation, mucus accumulation, ora foreign body can produce it.
In case of rigid obstruction, the wheeze is audible throughout the respiratory cycle, and when the obstruction is flexible, wheeze may be inspiratory or expiratory.
The intensity may change with a change in posture, as occurs in patients with partial bronchial obstruction by tumor. Fixed monophonic wheeze has a constant frequency and a long duration, whereas random monophonic wheeze has a varying frequency and duration present in both phases of respiration.
Random monophonic wheeze can be seen in asthma. Polyphonic wheezing consists of multiple musical notes starting and ending at the same time and is typically produced by the dynamic compression of the large, more central airways.
Polyphonic wheeze is confined to the expiratory phase only. The pitch of the polyphonic wheeze increases at the end of expiration as the equal pressure point moves towards the periphery.
Squawks are short inspiratory wheezes of less than msduration and are also known as squeaks. Acoustic analysis shows the fundamental frequency varying between and Hz. The exact mechanism is not known but, according to Forgacs, squawks are produced by the oscillations of peripheral airways in deflated lung zones when their walls remain in contact for a longer period of time and open in late inspiration.
Crackles are discontinuous, explosive, and nonmusical adventitious lung sounds normally heard in inspiration and sometimes during expiration. Crackles are usually classified as fine and coarse crackles based on their duration, loudness, pitch, timing in the respiratory cycle, and relationship to coughing and changing body position.
Medium crackles have also been mentioned. Fine crackles are produced within the small airways, medium crackles are caused by air bubbling through mucus in small bronchi, and coarse crackles arise from the large bronchi or the bronchiectatic segments. Initial deflection width IDW is the time duration ms between the beginning and the first deflection of the crackle above or below the baseline. Two-cycle duration 2CD is the duration between the beginning of the crackles and the first two cycles of the crackle [ Figure 3 ].
Initially, production of crackles was attributed to the passage of air through the accumulated secretions within the large and medium-size airways, creating the bubbling sounds.
However, persistence of crackles after coughing in many patients and predominant localization in inspiration argues against this theory. Later on, Forgacs proposed the second theory of crackles. According to Forgacs, small airways that were collapsed during expiration snap open during inspiration as a gradient of gas pressure is developed across the collapsed airways. Sudden explosive opening of the collapsed airways induces a rapid equalization of gas pressures resulting in oscillations of the gas column and development of crackles.
Fredberg and Holford proposed the stress relaxation quadrupole hypothesis of crackles generation in Crackles arise due to the sudden opening and closing of airway, resulting in stress waves' propagation in the lung parenchyma. Vyshedskiy et al. Almeida et al. Liquid bridges are formed due to abnormal mechanical instabilities in the small airways.
The lung sounds are best heard with a stethoscope. This is called auscultation. Absent or decreased sounds can mean: Air or fluid in or around the lungs such as pneumonia , heart failure , and pleural effusion Increased thickness of the chest wall Over-inflation of a part of the lungs emphysema can cause this Reduced airflow to part of the lungs There are several types of abnormal breath sounds. The 4 most common are: Rales.
Small clicking, bubbling, or rattling sounds in the lungs. They are heard when a person breathes in inhales. They are believed to occur when air opens closed air spaces. Rales can be further described as moist, dry, fine, or coarse. Sounds that resemble snoring. They occur when air is blocked or air flow becomes rough through the large airways.
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