Wheezing is caused by a narrowing of the airways.
Other symptoms depend on the cause and may include cough, fever, and runny nose.
The diagnosis of the cause is based on chest x-rays and sometimes other tests.
Treatment can include bronchodilators and corticosteroids.
(See also Wheezing Wheezing Wheezing is a high-pitched, whistling sound that occurs during breathing when the airways are partially blocked. (See also Wheezing in Infants and Young Children.) Wheezing results from a narrowing... read more in adults.)
Wheezing is caused by a narrowing or blockage (obstruction) of the airways. The narrowing can be caused by one or more of the following:
Swelling of the tissues in the airways
Spasm of the tiny muscles in the walls of the airways (bronchospasm)
Accumulation of mucus in the airways
Recurring episodes of wheezing are common in the first few years of life. Until recently, doctors diagnosed these episodes as asthma Asthma in Children Asthma is a recurring inflammatory lung disorder in which certain stimuli (triggers) inflame the airways and cause them to temporarily narrow, resulting in difficulty breathing. Asthma triggers... read more because, like asthma, episodes could be relieved by inhaling drugs that open the airways (bronchodilators) and because most adults who have asthma first developed symptoms in childhood. Now, however, doctors know that only some infants and young children who have such episodes of wheezing have asthma in later childhood or adolescence.
Did You Know...
Children who are more likely to be eventually diagnosed with asthma include children who have one or more of the following risk factors:
More severe wheezing episodes
Family members with asthma
A family tendency to have many allergies
Wheezing with viral illnesses (particularly those caused by respiratory syncytial virus Respiratory Syncytial Virus (RSV) Infection and Human Metapneumovirus Infection Respiratory syncytial virus infection and human metapneumovirus infection cause upper and sometimes lower respiratory tract infections. Respiratory syncytial virus is a very common cause of... read more and human rhinovirus Common Cold The common cold is a viral infection of the lining of the nose, sinuses, and throat. Many different viruses cause colds. Usually, colds are spread when a person's hands come in contact with... read more )
However, in most children, wheezing episodes stop by 6 to 10 years of age, and doctors do not diagnose these children as having asthma. Such children have other causes for their recurring episodes of wheezing.
The most common cause of a single, sudden episode of wheezing in infants and young children is usually a
Viral respiratory infection
The most common causes of recurring episodes of wheezing are
Frequent viral lung infections
Less common causes of recurring wheezing include chronic difficulty swallowing Difficulty Swallowing Some people have difficulty swallowing (dysphagia). In dysphagia, foods and/or liquids do not move normally from the throat (pharynx) to the stomach. People feel as though food or liquids become... read more that causes recurring inhalation of food or liquids into the lungs, gastroesophageal reflux Gastroesophageal Reflux in Children Gastroesophageal reflux is the backward movement of food and acid from the stomach into the esophagus and sometimes into the mouth. Reflux may be caused by the infant’s position during feeding... read more , a foreign object in the lungs, or heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more .
Whatever the initial cause of the wheezing, symptoms are often worsened by allergies or inhaled irritants (such as tobacco smoke).
Wheezing is often accompanied by a recurring cough Cough in Children Cough helps clear materials from the airways and prevent them from going to the lungs. The materials may be particles that have been inhaled or substances from the lungs and/or airways. Most... read more that is dry or brings up sputum (also called phlegm). Other symptoms depend on the cause and may include fever Fever in Infants and Children Normal body temperature varies from person to person and throughout the day (it is typically highest in the afternoon). Normal body temperature is higher in preschool-aged children and highest... read more , runny nose, and feeding difficulties (caused by heart failure or difficulty swallowing).
A high-pitched wheezing sound is heard when the child breathes out. If airway narrowing is severe, the wheezing sound can be heard when the child breathes in. Very ill children may also breathe rapidly, use a lot of their chest muscles to breathe, and have flaring of the nostrils and a bluish discoloration of the skin (cyanosis Cyanosis Cyanosis is a bluish discoloration of the skin resulting from an inadequate amount of oxygen in the blood. Cyanosis occurs when oxygen-depleted (deoxygenated) blood, which is bluish rather than... read more ). Fever may be present in children with a lung infection.
Rarely swallowing studies, computed tomography, or bronchoscopy
For a first episode of severe wheezing, most doctors do a chest x-ray Chest Imaging Chest imaging studies include X-rays Computed tomography (CT) CT angiography Magnetic resonance imaging (MRI) read more to look for signs of a foreign object in the lungs, pneumonia, or heart failure. Doctors measure oxygen levels in the blood by placing a sensor on a finger (pulse oximetry Pulse oximetry Both arterial blood gas testing and pulse oximetry measure the amount of oxygen in the blood, which helps determine how well the lungs are functioning. Arterial blood gas tests are invasive... read more ).
For children with recurring episodes of wheezing who have already had testing, flare-ups typically do not require testing unless there are signs of severe breathing problems. Children who have frequent or severe flare-ups or symptoms that are not relieved by bronchodilators or other asthma drugs may need other tests such as swallowing studies X-Ray Studies of the Digestive Tract X-rays often are used to evaluate digestive problems. Standard x-rays (plain x-rays) do not require any special preparation ( see Plain X-Rays). These x-rays usually can show a blockage or paralysis... read more , computed tomography Computed Tomography (CT) In computed tomography (CT), which used to be called computed axial tomography (CAT), an x-ray source and x-ray detector rotate around a person. In modern scanners, the x-ray detector usually... read more (CT), or bronchoscopy Bronchoscopy Bronchoscopy is a direct visual examination of the voice box (larynx) and airways through a viewing tube (a bronchoscope). A bronchoscope has a camera at the end that allows a doctor to look... read more .
For flare-ups, bronchodilators and sometimes corticosteroids
For severe wheezing, daily use of bronchodilators and anti-inflammatory drugs used for asthma
Infants and young children who have flare-ups of wheezing are given an inhaled bronchodilator (such as albuterol) and, if the wheezing is severe, corticosteroids (such as prednisone) given by mouth or vein.
Children who are unlikely to develop persistent asthma, such as children who do not have signs of allergies or a family history of allergies or asthma and whose episodes of wheezing are relatively mild and infrequent, usually require only inhaled bronchodilators used as needed to control their symptoms.
Most young children with more frequent and/or severe episodes of wheezing are helped by as-needed use of bronchodilators and by daily use of anti-inflammatory drugs that are used for asthma ( see Chronic asthma Chronic asthma Asthma is a recurring inflammatory lung disorder in which certain stimuli (triggers) inflame the airways and cause them to temporarily narrow, resulting in difficulty breathing. Asthma triggers... read more ). Although daily use of a leukotriene modifier (such as montelukast or zafirlukast) or a low-dose inhaled corticosteroid (such as beclomethasone) decreases the severity and frequency of episodes of wheezing, these drugs do not change the way the disorder naturally progresses.