What is Wheezing?
Wheezing can be a symptom of different illnesses that cause blockage in the airways. Thanks to the invention of the stethoscope by Rene Laennec in 1816, doctors are now able to identify wheezing more accurately, compared to the old method of directly listening to the chest. Wheezing is a musical, high-pitched sound that can be created anywhere from the voice box to the tiny air passages in the lungs during breathing in or out. Present technology allows us to describe wheezing more precisely. It usually appears as a wave pattern with a specific frequency and duration.
Sometimes, the wheezing sound can be loud enough to hear without a stethoscope, but in most cases, a stethoscope is used to listen for it. Even though wheezing is a common symptom of asthma, it doesn’t necessarily mean that a person has asthma. A thorough medical history and physical examination are vital in accurately diagnosing the cause of the wheezing.
What Causes Wheezing?
Wheezing, which is a whistling sound when you breathe, is commonly associated with asthma but can also occur if someone has a foreign object lodged in their respiratory system, heart failure, cancer in the breathing tubes or any other condition that results in the narrowing of these airways. During the out-breath, or exhalation, if a person is wheezing, it indicates they are not able to breathe out as strongly as normal.
The type and length of the wheezing can depend on where the narrowing in the airways is. In asthma, the wheezing comes from the narrowing of the lower breathing tubes, while in cases with cancers, the narrowing usually occurs in the upper, closer to the mouth and nose, airways. In rare cases, the wheezing sound can happen when both breathing in and out.
In severe cases of asthma, there may not be a wheeze because the air flow might be too restricted, and you won’t hear anything when listening to the chest. Since a wheeze can be made by any process that narrows the size of the airway, below are just a few conditions that can cause wheezing:
Respiratory infections like croup, laryngitis, and bronchiolitis; Obstructive airway diseases like asthma or chronic obstructive pulmonary disease (COPD); Severe allergic reactions (anaphylaxis); Swelling around the smaller breathing tubes due to heart failure; Dysfunction of the vocal cords; Nasal fluids dripping into the throat; Compression of the airway, both from the inside (like in squamous cell carcinomas or cancer) or the outside (like with an enlarged thyroid); Collapse of the airway; Carcinoid tumors; Choking on a foreign object; Or even forceful exhalation by a healthy individual.
Risk Factors and Frequency for Wheezing
Wheezing is fairly common in young children, particularly those aged 2 to 3 years, with about 26% of kids in the United States experiencing it. However, as children grow into adolescence, this rate tends to decrease worldwide to about 12%. The same rate is observed in adults, with the highest occurrence noticed in Europe and Australia where up to 17% of the population may experience wheezing.
Signs and Symptoms of Wheezing
When considering the several reasons someone might have a wheezing sound when breathing, it’s essential to understand their medical history. For instance, if someone has had surgery or radiation treatment for head and neck cancer, they could develop vocal cord paralysis. It’s also good to know if the patient has ever had a breathing tube inserted in the hospital, as this might point to a narrowing of the windpipe or the area just below the vocal cords.
The doctor will usually listen to your chest and throat to identify any wheezing. Wheezing is often associated with asthma, and it’s typically heard when you breathe out. However, it’s important to remember that wheezing can also be heard when you breathe in and is not always a sign of asthma. The doctor may also examine the mouth to check for enlarged tonsils that can block the airway. The neck might also be checked in order to spot any thyroid swellings, known as goiters.
Testing for Wheezing
If you begin to hear a whistling sound, known as wheezing, when you breathe, it will likely require further examination by your doctor. The whistling sound is abnormal and might indicate a problem with your lungs or airways.
Usually, the first thing your doctor will do is to conduct a chest x-ray. This is done to check if something foreign is stuck in your lungs or if there’s a lesion (an area of damaged tissue) in your airway.
If your doctor thinks you may have asthma, but it isn’t an emergency situation, they will perform what’s called pulmonary function tests. These tests measure how well your lungs are working. Then, you might be given a bronchodilator—a medication that opens the airways in the lungs—to see if it improves your condition.
If the wheezing goes away after the bronchodilation agent is used, then it is less likely that the issue is caused by a tumor or mass. If there’s no improvement after the treatment, and your doctor suspects a tumor or mass, you might require a CT scan of the chest area.
A CT scan provides more detailed images of your organs, bones, and tissues than an x-ray. If the CT scan suggests the possibility of cancer, a bronchoscopy might be needed. Bronchoscopy is a procedure to look inside the airways in the lungs. It uses a thin, flexible tube called a bronchoscope to view the airways and take biopsies if needed.
Treatment Options for Wheezing
Treatment options for wheezing mostly depend on the underlying cause. The first and foremost approach is to ensure the stability of the patient’s airway, breathing, and circulation, often referred to as ‘ABC.’ In severe cases, where the patient may be near respiratory failure, they may require assistance with their breathing. This could be either non-invasive (using a mask and positive pressure to help push air into the lungs) or invasive (using a breathing tube and a ventillator). If the wheezing is caused by a severe allergic reaction, known as anaphylaxis, a medication called epinephrine (or adrenaline) may be used.
While the doctors are determining the exact cause of the wheezing, they often provide medications that can be inhaled directly into the lungs. These typically include albuterol, which helps to open up the airways, and muscarinic antagonists, which also help the muscles around the airways to relax. Both of these drugs aim to provide relief from symptoms and make breathing easier. They are administered using a device called a nebulizer, which turns the medication into a fine mist that can be easily inhaled, especially in severe wheezing situations.
What else can Wheezing be?
While wheezing is a common symptom in several lung conditions, it can often be confused with similar sounds like rhonchi and stridor. Rhonchi are similar to wheezes but they resonate at a lower frequency which makes them sound more like snoring. On the other hand, stridor is a high-pitched sound caused by air rushing through a blocked airway, and it is usually more noticeable when you’re listening to the trachea rather than the chest.
There are several possible reasons someone might wheeze, including:
- Allergies
- An extreme allergic reaction, known as anaphylaxis
- Asthma
- Bronchiectasis, or a widening of the airways
- Bronchiolitis, inflammation of the small airways
- Bronchitis, or an inflammation of the main air passages
- Chronic obstructive pulmonary disease (COPD)
- Emphysema, a lung condition that causes shortness of breath
- Epiglottitis, swelling of the flap at the back of the tongue
- A foreign object in the airway
- Gastroesophageal reflux disease (GERD)
- Heart failure
- Lung cancer
- Reactions to certain drugs, like aspirin
- Obstructive sleep apnea
- Pneumonia, an infection that inflames the air sacs
- Respiratory syncytial virus (RSV), a common virus that affects the lungs
- A respiratory tract infection
- Smoking
- Vocal cord dysfunction