The movement of air in and out of the lungs and airways causes a sound that we refer to as the breathing sounds or respiratory sounds. When inhaling, the air flowing from the environment into the lungs or mouth, down the airways and to the lungs is known as the inspiratory or inhalation respiratory sound. Air flowing out of the lungs, up the airways and out through the mouth or nostrils is known as the expiratory or exhalation respiratory sound.
Why is breathing sounding like a whistle?
Most of the time we ignore our own respiratory sounds unless it becomes abnormal. There are many different types of abnormal breathing sounds and the most commonly known of these sounds is a wheeze. The other types include crackles, rhonchi, stridor, crackles and pleural friction rub. From the different abnormal breathing sounds, it is important to consider the causes of wheeze and stridor since these sounds are typically like a whistle.
Read more on abnormal breathing sounds.
- Wheezing is the high-pitched whistling sound that is heard when breathing. It may be present when inhaling (inspiratory wheeze) or exhaling (expiratory wheeze) and is usually a sign of narrowing of the lower airways.
- Stridor is another type of high-pitched whistling sound that is heard with breathing. It occurs when there is a narrowing in the upper airway in contrast to wheezing where the narrowing is in the lower airways.
Most people to have difficulty differentiating between a wheeze and stridor. Since wheezing is a more commonly known term, a stridor may also be sometimese described as a wheeze. Furthermore the causes of a stridor may overlap to affect the lower airways just as the causes of a wheeze may also involve the upper airway. Nevertheless both can be said to be an abnormal wheezing sound when breathing.
Reasons for Whistling When Breathing
A whistling sound in the respiratory system is caused by disturbances in air flow, mainly when the air is forced to move through narrower tracts. This causes an air vortex which in turn produces sound, and in this case a high pitched sound which is described as a whistle. Objects or other defects that can deflect air movement may also cause similar air vortices and result in a whistling sound.
Most of the time a wheeze or stridor is accompanied by varying degrees of breathing impairment. This may range from shortness of breath to difficulty breathing. It is important to seek immediate medical attention if the difficulty with breathing is severe or worsening. Other signs like pale skin or a bluish tinge of the skin, dizziness, confusion and/or fainting that accompany difficulty breathing should also be considered as red flags.
Causes of Whistling Breathing Sounds
As mentioned, any condition that causes narrowing of the airways can cause a whistling breathing sound. This narrowing may be due to swelling of the airway walls (often due inflammation), mucus buildup in the airways and less commonly due to physical obstructions such as a growth or a foreign object. Always consult with a medical professional to diagnose the exact cause of a whistling breathing sound.
Read more on causes of wheeze and stridor.
The most common allergic condition that leads to whistling breathings sounds is allergic asthma. In this condition the bronchial tubes narrow due to immune mediated hypersensitivity. It is more common among children but can affect any age group. Another allergic condition that can lead to wheezing is hypersensitivity pneumonitis where the lung becomes inflamed due to an allergy. It is more likely to be linked to occupational exposure to allergens.
The upper airways may also be inflamed due to allergies, as is the case in allergic laryngitis. The more serious acute allergic response where a whistling sound may be heard is in an anaphylactic reaction. This is a serious condition where the airways narrow suddenly due to exposure to a certain allergen. Anaphylaxis can be life-threatening and needs immediate medical attention.
Respiratory tract infections are one of the most common acute causes of whistling sounds when breathing. Viruses and bacteria cause the maority of both upper and lower respiratory tract infections. This includes the viruses and bacteria that causes epiglottitis, laryngitis, tracheitis, bronchitis and bronchiolitis. People with other respiratory diseases such as asthma, may also experience an exacerbation of these conditions during an acute infection.
A whistling breathing sound and barking cough is characteristic of croup. This is an upper airway infection of the larynx and trachea that may extend down to the bronchi. Violent, rapid coughing with a high pitched inhalation after coughing is characteristic of pertussis, also known as whooping cough. Croup is due to viruses whil pertussis is caused by the bacteria, Bordetella pertussis. Both are highly contagious.
Allergies and infections account for most cases of acute conditions that lead to a whistling breathing sound. However, there are other conditions that may also be responsible, with some being more common than others.
- Foreign body: An object in the airway can cause a whistling breathing sound and is more likely to be seen among young children who swallow non-edible objects such as beads, small balls and coins.
- COPD: Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis where there bronchi is inflamed and emphysema where the air sacs are destroyed. Both are linked to long term smoking.
- GERD: Gastroesophageal reflux disease (GERD) or acid reflux can also cause a whistling breathing sound when the acid enters the airways (aspiration) thereby causing airway inflammation.
- Sleep apnea: Obstructive sleep apnea is where the tissue at the back of the throat relax and collapse thereby preventing air flow. A person stops breathing momentarily when asleep.
- Heart failure: In heart failure the heart’s ability to pump blood is compromised to varying degrees. One of the possible consequences is fluid collection in the lungs (pulmonary edema).
- Lung cancer: A malignant (cancerous) growth causes destruction of the lung tissue and may also extend to the airways over time.