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Wheezing describes a form of difficult, noisy breathing.
What is going on in the body?
Wheezing is often described as a whistling or squeaking noise that occurs when people breathe. It is thought to occur due to narrowed airways. When the airways are narrowed from any cause, the air passing through them may make the noise known as wheezing. Wheezing usually occurs when a person breathes out, or exhales, but may also occur when a person breathes in, or inhales. There are many possible causes.
What are the signs and symptoms of the condition?
If someone complains of wheezing, the doctor will need more information. Questions may be asked related to:
Sometimes a doctor will detect wheezing during a physical examination when the person doesn't even notice it.
- when the wheezing started
- whether there is any family history of wheezing
- whether the wheezing is constant or comes and goes
- what medications, herbs, or illegal drugs a person takes, if any
- whether or not the person has been exposed to any substances that may irritate the lungs, such as tobacco smoke or industrial chemicals
- what other medical conditions a person has, especially heart and lung conditions
- if anything makes the wheezing worse or better, such as staying inside or being around cats
- any other symptoms, such as fever, weight loss, or cough
What are the causes and risks of the condition?
Wheezing has many possible causes, including:
Other causes are also possible. Sometimes no cause can be found.
- asthma, a condition that causes reversible narrowing of the airways. This usually occurs after exposure to certain triggers, such as pollen, cold air, or exercise.
- chronic obstructive pulmonary disease, or COPD, which includes emphysema and chronic bronchitis. This is usually due to smoking cigarettes.
- heart conditions, such as congestive heart failure and mitral stenosis, a disorder that affects one of the valves of the heart
- cancer or a tumour, particularly primary lung cancer
- heartburn, also called gastro-oesophageal reflux disease
- allergic reactions, which may be from medications such as penicillin or aspirin, or due to exposure to cat hair, bee stings, a certain food, or some other substance
- infections, such as pneumonia, or an infection usually seen in children called bronchiolitis
- a foreign body somewhere in the windpipes. This commonly occurs in young children who can accidentally inhale small objects they put into their mouths.
- cystic fibrosis, an inherited condition that mainly affects the lungs and digestion
- inflammation of the lung from other conditions, such as a disorder known as sarcoidosis
What can be done to prevent the condition?
Prevention is related to the cause. For instance, avoiding smoking can prevent most cases due to emphysema or lung cancer. Keeping small objects away from young children can prevent some cases due to a foreign body. Many cases cannot be prevented.
How is the condition diagnosed?
The first step in figuring out the cause is a history and physical examination. This may be all that is needed to make the diagnosis. In other cases, further tests may be needed.
Different tests may be ordered, depending on the suspected cause. For instance, a type of breathing test called pulmonary function testing can help diagnose asthma and COPD. Chest x-rays are commonly used, and can help detect pneumonia, sarcoidosis, and other conditions. Special x-ray tests, such as a chest CT scan, may be needed in certain cases. For instance, a CT scan can help detect lung cancer.
What are the long-term effects of the condition?
Wheezing is a form of difficulty in breathing. Those with severe narrowing in multiple areas of their airways may die if they cannot take in enough air. Other long-term effects are related to the cause. For instance, cancer can result in death even if the wheezing stops.
What are the risks to others?
Wheezing itself is not contagious. But if the cause is an infection, such as pneumonia, the infection may be contagious.
What are the treatments for the condition?
Medications to help open up narrowed airways can be used in many cases to help stop the wheezing and make breathing easier. Examples of these medications include salbutamol and ipratropium. In severe cases of wheezing when the person cannot breathe effectively, a ventilator, or artificial breathing machine, may be needed.
Treatment is then directed at the cause, when possible. For instance, antibiotics can be used to treat pneumonia. Medications can be used to control heartburn. Medications to reduce inflammation are often helpful in asthma, sarcoidosis, and COPD. Surgery, chemotherapy, or radiation therapy may be needed to treat a tumour or cancer.
What are the side effects of the treatments?
Side effects depend on the treatments used. All medications have possible side effects. For instance, antibiotics may cause allergic reactions, stomach upset, or headache. A ventilator may cause damage to the lungs or cause a lung infection. Surgery carries a risk of bleeding and infection.
What happens after treatment for the condition?
Severe wheezing from almost any cause may result in death if treatment is unsuccessful. What happens after treatment otherwise depends on the cause. Most cases of wheezing are usually cured after treatment, such as pneumonia or heartburn.
How is the condition monitored?
A person with moderate or severe wheezing is often admitted to the hospital for close monitoring. A person with mild wheezing may be given treatments to use at home. Any worsening of symptoms should be reported to the doctor right away. Other monitoring is related to the cause. For instance, A person with lung cancer may need repeated x-ray tests to follow the tumour and its response to treatment.
Author: Adam Brochert, MD
Reviewer: eknowhow Medical Review Panel
Editor: Dr John Hearne
Last Updated: 16/09/2004
Potential conflict of interest information for reviewers available on request