Asthma is a chronic lung disease that causes inflammation and narrowing of the airways. It affects over 25 million Americans and is one of the most common chronic diseases in children. Asthma causes symptoms like wheezing, chest tightness, coughing, and shortness of breath. These symptoms can range from mild to severe and can sometimes be life-threatening. Knowing the main symptoms of asthma is important for properly diagnosing and managing the condition. So what is the number one, most common symptom that indicates asthma?
Wheezing
Wheezing is the whistling or squeaky sound that occurs when breathing, especially when exhaling. It is caused by the narrowing of airways, which makes it difficult for air to move in and out of the lungs. Wheezing is the hallmark symptom of asthma and is present in nearly all asthma sufferers.
During an asthma attack or flare-up, the muscles around the airways tighten and the airways become inflamed and swollen. This narrows the airways and less air is able to flow through, forcing the air to squeeze through the narrowed opening. This creates the characteristic wheezing sound as the person struggles to breathe.
Wheezing may be more noticeable when breathing out, since exhalation requires more effort when the airways are constricted. It can range from soft and high-pitched to very loud depending on the severity of airway narrowing. Some people describe wheezing as a whistling, squeaking, or gasping sound.
What Causes the Wheezing
The wheezing is primarily caused by bronchospasm or narrowing of the bronchial tubes in the lungs. Several factors can trigger this airway narrowing:
- Inflammation – During asthma attacks, the airway lining becomes inflamed and swollen. This inflammation narrows the inside diameter of the airways.
- Bronchoconstriction – The bands of muscle surrounding the airways contract, causing them to tighten up and become narrower.
- Excess mucus – Extra mucus production can clog the airways.
As the airways narrow from these factors, airflow is restricted, forcing the air through the small openings and creating a wheezing sound.
Why Wheezing Occurs Mostly on Exhalation
Wheezing is often louder when exhaling because of the increased effort required to push air through the narrowed airways.
When inhaling, air is pulled into the lungs by the diaphragm expanding and the chest wall muscles contracting. This generates negative pressure that draws air into the airways. Even with narrowed airways, enough air is typically able to flow in to fill the lungs.
Exhalation requires positive pressure generated by the diaphragm and chest wall muscles relaxing and compressing the lungs to push air out. This takes more exertion when the airways are narrowed by bronchospasm or inflammation. The increased force to exhale through the obstructed airways causes air turbulence and the wheezing sound.
Prevalence of Wheezing in Asthma
Studies show that wheezing is present in the vast majority of asthma patients:
- A study published in the Annals of Allergy, Asthma & Immunology found that 94% of asthma patients reported wheezing during an asthma attack. It was the most common symptom.
- Research in the European Respiratory Journal found wheezing in 86% of asthma patients versus only 15% of people without asthma.
- A study in Primary Care Respiratory Medicine showed wheezing was experienced by 89% of asthma patients, compared to 13% of the control group.
This data demonstrates that wheezing is experienced by the large majority of people with asthma and is significantly more common in asthmatics compared to the general population.
Age Differences in Wheezing
Wheezing is the most characteristic asthma symptom in patients of all ages, but some research shows it may be reported more often by certain age groups:
- A study in the Journal of Allergy and Clinical Immunology found wheezing was reported in 100% of children under 5 years old hospitalized for asthma.
- Research in the Indian Journal of Pediatrics showed wheezing in over 90% of children ages 1 to 15 years with asthma.
- A study in Annals of Allergy, Asthma & Immunology found wheezing in 89% of asthma patients ages 18 to 39 years old.
- Another study showed adults over age 55 may have less audible wheezing, but experience more chest tightness.
Younger children may be more likely to vocalize wheezing when breathing, while some older patients have “silent” wheezing. But it remains the predominant symptom across ages.
Other Common Asthma Symptoms
While wheezing is the primary symptom, asthma can also cause other respiratory symptoms:
Coughing
Coughing is another common asthma symptom that affects 75-90% of asthma sufferers. Chronic coughing may occur throughout the day or at night. Coughing may be the only symptom in some cases. Asthma is one of the most frequent causes of chronic cough in adults and children.
In asthma, coughing may occur due to:
- Inflammation and irritation of the airways
- Increased production of mucus, which triggers cough reflex
- Bronchoconstriction
Coughing forcefully can help clear mucus and irritants from the airways. But excessive coughing can make asthma worse by further inflaming the airways.
Shortness of Breath
Shortness of breath, also called dyspnea, refers to difficult or labored breathing. Around 75% of people with asthma experience episodes of shortness of breath.
Narrowed, constricted airways make it harder to move air in and out of the lungs. The effort to breathe can create a feeling of tightness in the chest and shortness of breath. This sensation tends to get worse during an asthma attack.
Some people describe asthma-related shortness of breath as:
- Feeling like they can’t get enough air
- Having to work hard to breathe
- Feeling smothered or suffocated
Exertion can also trigger shortness of breath in people with asthma.
Chest Tightness
Around 70% of asthma patients experience chest tightness or pain. This symptom is sometimes called chest congestion.
The inflamed, constricted airways make it feel like the chest is being squeezed or compressed. There is a sensation of heaviness or tightness that can range from mild to severe. Deep breaths may hurt.
Some people describe the chest tightness as:
- Feeling like a weight is sitting on the chest
- Having a sore or bruised feeling in the chest
- A choking sensation
For some, chest tightness may be the most bothersome symptom of asthma because it can create feelings of anxiety or panic.
Triggers for Asthma Symptoms
Many different things can trigger or worsen asthma symptoms like wheezing and coughing. Common asthma triggers include:
Respiratory Infections
Colds, sinus infections, bronchitis, and pneumonia can all aggravate asthma. The infection causes further inflammation and swelling of the airways on top of the existing inflammation in the lungs. Around 60-70% of asthma exacerbations in children are caused by respiratory infections.
Allergens
Allergic reactions to things like pollen, pet dander, mold, and dust mites can trigger asthma flares. When exposed to an allergen, the immune system overreacts and causes swelling in the airways. About 80% of people with asthma have allergies.
Irritants
Irritating substances like cigarette smoke, air pollution, chemicals, and strong odors can induce asthma symptoms. They irritate the airways and cause them to spasm and swell.
Exercise
Physical activity is a common asthma trigger, especially in children. It can cause bronchospasm and difficulty breathing. But staying active provides many health benefits, so asthma patients should work with their doctor to manage exercise-induced symptoms.
Weather Changes
Some people’s asthma is exacerbated by cold, dry air or changes in weather and humidity. These can irritate the airways and instigate asthma flare-ups.
Medications
Some medications like aspirin and beta blockers are known to provoke asthma symptoms in susceptible individuals. People with asthma should notify all of their doctors about their condition.
Stress and Emotions
Research indicates psychological stress, anxiety, strong emotions, and laughter can sometimes trigger asthma exacerbations, likely by impacting airway inflammation. Finding healthy ways to manage stress is helpful.
Gastroesophageal Reflux Disease (GERD)
GERD occurs when stomach acid flows back up into the esophagus. This can irritate the airways and cause asthma symptoms like wheezing, coughing, and chest tightness. Treating acid reflux may help control asthma.
Hormonal Changes
Shifts in hormones may worsen some people’s asthma, like during puberty, menstruation, pregnancy, menopause, or oral contraceptive use. The mechanisms for hormonal impact on asthma are still being investigated.
Diagnosing Asthma with Lung Function Tests
Since wheezing and other asthma symptoms can also be signs of other lung conditions, doctors use lung function tests to diagnose asthma:
Spirometry
This is the main test to diagnose asthma. Spirometry measures how much air you can breathe out in one forced breath and how fast you can blow air out. Patients with asthma typically show obstruction and limitation of exhaled airflow.
Bronchoprovocation Testing
This test triggers and assesses any breathing reactions you may have to methacholine, cold air, exercise, or other stimuli. People with asthma will react with decreased airflow when exposed to a trigger.
Peak Flow Monitoring
This involves blowing into a peak flow meter device to measure your maximum expiratory airflow rate. Asthma patients have variability and decreases in peak flow rates.
Exhaled Nitric Oxide Test
This measures nitric oxide gas levels in your exhaled breath, which are higher when you have uncontrolled asthma and airway inflammation.
Chest X-ray
Can identify lung inflammation associated with asthma, but lung changes may be minimal in mild asthma. Mainly rules out other lung diseases.
Allergy Testing
Done through skin or blood tests. Can identify if allergies are an asthma trigger for a patient. Knowing allergy triggers helps avoid asthma attacks.
Treating Asthma with Medications
While there is no cure for asthma, medications can effectively control symptoms in most patients:
Quick Relief Medications
Quick-relief or rescue medications quickly relax tightened airway muscles to relieve acute asthma symptoms:
- Short-acting beta-agonists like albuterol relax airway muscles
- Ipratropium blocks acetylcholine that triggers bronchospasm
- Oral corticosteroids reduce inflammation
These fast-acting medications provide temporary symptom relief and are used as needed.
Long-Term Control Medications
Preventative, long-term control medications are used daily to manage asthma in the long run:
- Inhaled corticosteroids reduce inflammation
- Long-acting beta-agonists relax airway muscles
- Leukotriene modifiers block inflammatory leukotrienes
- Immunomodulators reduce sensitivity to triggers
These medications prevent asthma flare-ups and keep asthma under control. They treat the underlying disease process.
Allergy Medications
For asthma triggered by allergies, allergy medication can help prevent symptoms:
- Antihistamines block histamine released in allergic reactions
- Nasal corticosteroids reduce inflammation
- Immunotherapy can help desensitize you to allergens
Controlling allergies and allergy flares prevents associated asthma attacks.
Treatment of Comorbid Conditions
Conditions linked to asthma like acid reflux and sinusitis also need to be treated to help control asthma symptoms and exacerbations. An integrated treatment approach works best.
Lifestyle Changes to Control Asthma
Besides medication, lifestyle adjustments can improve asthma control:
- Avoid known asthma triggers
- Use an air purifier and dehumidifier
- Limit outdoor time when pollution and pollen counts are higher
- Stick to a healthy diet and active lifestyle
- Maintain a healthy weight
- Manage stress and practice relaxation techniques
- Get flu and pneumonia vaccines
- Do not smoke and avoid secondhand smoke
Making lifestyle changes, in addition to taking prescribed asthma medications, helps gain better control over symptoms.
When to Seek Emergency Treatment
Severe asthma attacks can be life-threatening, so urgent medical care is needed if:
- Short-acting inhalers provide no relief
- Breathing is very difficult and fast
- Cannot complete a sentence without stopping to breathe
- Lips or fingernails are blue or gray
Other danger signs include drowsiness, confusion, low blood oxygen, and low peak flow meter readings. If symptoms do not improve with medication or you are concerned, go to the emergency room or call 911.
Conclusion
Wheezing is the most common and prominent symptom of asthma. It is caused by airway narrowing and irritation. Wheezing affects the majority of asthma sufferers and is a key characteristic that helps diagnose the condition. While asthma has other typical symptoms like coughing and shortness of breath, wheezing is the primary and cardinal symptom of this widespread lung disease. Controlling wheezing and preventing asthma exacerbations that trigger wheezing requires a combination of medication, trigger avoidance, and lifestyle changes. But even with good asthma control, wheezing is still likely to occur at times in most asthma patients.