What Is Asthma? Symptoms, Causes, Diagnosis, Treatment, and Prevention
Asthma is a common chronic (long-term) lung disease in which the lungs’ bronchial tubes, or airways, become inflamed.
This inflammation causes the airways to become sensitive to environmental triggers, such as dust, smoke, pet dander, or cold air.
In reaction to these triggers, an asthma attack can occur. The muscles around the bronchial tubes tighten, the lining of the airways becomes inflamed, and the airways overproduce mucus, making it difficult to breathe.
Want to know more about asthma? Read on to learn what experts know about this breathing disorder, why some people develop it and others don’t, lifestyle changes that can help you manage asthma, and how to avoid complications linked to the condition.
Asthma is a disease that affects your airways, which carry air in and out of your lungs. The type of asthma you have depends on your specific triggers.
Thanks to advances in asthma research, doctors have been able to identify the different types of asthma. The most common types of asthma are: exercise-induced bronchospasm (EIB), allergic asthma, nonallergic asthma, cough-variant asthma, occupational asthma, and nocturnal or nighttime asthma. EIB occurs after physical exertion. It’s not always easy to determine which type of asthma you have. Proper diagnosis and regular communication with your doctor can help you to determine the best course of action.
Asthma is a chronic lung disease, so it’s important to receive treatment as soon as possible to ensure that your condition doesn’t worsen.
Doctors differentiate severe asthma from other, milder forms of asthma according to the frequency and intensity of a person’s symptoms.
For starters, severe asthma is persistent, which doctors define as asthma that causes symptoms more than twice a week, explains Patricia Takach, MD, an associate professor of clinical medicine in the section of allergy and immunology at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia. For many severe asthma sufferers, symptoms occur daily.
Also, people with severe asthma require a mixture of medications that includes a high-dose inhaled corticosteroid or a systemic (oral) corticosteroid. Around the world, about 4 to 5 percent of people with asthma have severe asthma.
Also, and somewhat confusingly, severe asthma is not the same as a “severe acute asthma” attack or episode. This term refers to an asthma attack that is so severe that it requires immediate medical attention.
Coughing? Wheezing? Chest pain? If these symptoms sound familiar, it might be asthma, a chronic disease that inflames the airways (bronchial tubes) that carry air in and out of the lungs.
When something triggers your asthma symptoms, the membrane lining your airways swells, the muscles around the tubes constrict, and the airways fill with mucus. As these tubes narrow it becomes more difficult to breathe, causing symptoms such as wheezing and coughing, congestion, shortness of breath, and chest tightness or pain. If you have asthma, performing normal daily activities can be strenuous, and it may take longer to recover from a respiratory infection, such as a cold or flu.
An asthma attack or flare-up is a sudden worsening of these symptoms, including severe wheezing, uncontrollable coughing, rapid breathing, sweating, and anxiety. These symptoms require immediate medical attention.
But not everyone experiences asthma in the same way. Symptoms vary from person to person, can change with age, differ between attacks and may intensify during exercise, with a cold, or under periods of elevated stress.
It’s unknown what exactly causes asthma, but scientists believe that both genetic and environmental factors play a role in the development of the disease.
Why Do You Have Asthma?
Asthma tends to run in families, suggesting there’s an inherited component to the disease. You’re more likely to have asthma if your parents have it.
You’re also more likely to have asthma if you have atopic syndrome, or atopy — a predisposition toward certain allergic hypersensitivity reactions, such as atopic eczema and hay fever (allergic rhinitis). Asthma and allergies often go hand in hand.
Similarly, research suggests that early contact with airborne allergens, irritants, and certain viral infections — in infancy or early childhood, before the immune system is fully developed — raises your risk of developing asthma.
What Triggers an Asthma Attack?
Numerous triggers can cause asthma attacks, including:
Tobacco Smoke While smoking is unhealthy for anyone, it’s particularly dangerous for people with asthma. If you smoke, you should quit. Secondhand smoke can also trigger an asthma attack. Avoid situations in which people around you smoke. Also don’t let people smoke in a place where you spend a lot of time, such as your home or car — even if you’re not present when they smoke.
Smoke From Wood or Grass Even though it may seem “natural,” smoke from these sources contains harmful gases and particles. Avoid burning wood in your home. If you live in an area where wildfires occur, monitor air quality forecasts and try to stay inside when particle levels are at their worst.
Outdoor Air Pollution Emissions from factories, cars, buses, lawn mowers, leaf blowers, and snow blowers can all trigger an asthma attack. Try to avoid exposure to these sources whenever possible.
It’s also a good idea to check air quality measurements related to pollution in your area, such as ozone and small particles, and to stay inside as much as possible when they’re elevated.
Certain Foods and Food Additives While almost any food can cause an allergic reaction, a few additives (like sulfites and other preservatives) are widely believed to cause adverse reactions in some people. Acid reflux can also trigger an asthma attack in some people, so any food that aggravates this condition may also be responsible for symptoms.
Respiratory Infections These include influenza (flu), the COVID-19 virus, the common cold, respiratory syncytial virus (RSV), and sinus infections.
Strong Emotional States Negative emotions like stress, anxiety, depression, or fear can cause an attack, often by causing hyperventilation (heavy, fast breathing).
Certain Medications While different people have different triggers, common culprits include aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil) and naproxen (Aleve).
If you notice yourself having trouble breathing, wheezing, or having chest tightness, let your doctor know so he or she can determine if you have asthma or if something else is wrong. In some cases your primary care provider will refer you to a specialist for a diagnosis.
Diagnosing asthma typically involves your doctor taking your personal and medical history (asking you questions about your symptoms, asking you about your health history, and asking you about your family history); a physical exam (during which the doctor will listen to you breathe); and a pulmonary function test (a type of breathing test to evaluate your lung function).
Your doctor may run additional tests to help determine the type of asthma you have and to determine the severity of it. The type of asthma and its severity will help the doctor come up with an appropriate treatment plan for you.
In rarer cases, your doctor may also use a breath test called a fractional exhaled nitric oxide (FeNO) test to assess the level of inflammation in your lungs if it’s not clear whether you have asthma based on the results of other tests.
In younger children, doctors may diagnose asthma based on only symptoms, a family history, and a physical exam. Though in children 5 years old and older, the steps taken to diagnose asthma tend to be the same as in adults.
For adults with asthma, the condition is usually chronic — meaning they will have it for the rest of their life. A 2015 study found that only 3 percent of adults who had developed asthma experienced a remission of their symptoms during 12 years of follow-up.
The prognosis for asthma is different for children than for adults.
Some kids who develop asthma “lose” it as they grow older. While asthma may return later in life for some of them, many never have an asthma recurrence.
But for others, especially kids with severe asthma, the condition may not ever go away.
For all these reasons, the long-term prognosis for someone with asthma varies a lot. Some people get better over time — though their symptoms never fully go away — while others get worse, says Emily Pennington, MD, a pulmonologist and asthma specialist at the Cleveland Clinic in Ohio.
Fortunately, by working closely with a doctor to manage symptoms — with medication, and also by avoiding asthma triggers — most people with asthma can live a normal, healthy life free of asthma-related complications.
There is no cure for asthma, but you can alleviate and prevent your symptoms through quick-relief and long-term control medication. Long-term control medication works to reduce inflammation to make your airways less sensitive to asthma triggers. It’s usually taken daily through an inhaler or as an oral pill. Quick-relief medicines help to relieve symptoms when they happen, relaxing the tight muscles around your airways and easing the flow of air.
The asthma management guidelines, updated in December 2020 by the National Asthma Education and Prevention Program, recommend using one inhaler containing an asthma medication that combines an inflammation-reducing corticosteroid plus the drug formoterol to open airways for people ages 12 and older — teens and adults whose moderate to severe persistent asthma is not well controlled with their current medication. This combination therapy is called single maintenance and reliever therapy (SMART).
The updated guidelines also recommend a type of drug called a long-acting muscarinic antagonist to improve symptoms as an alternative for these age groups when standard combination therapy cannot be used. And for young children (up to age 4) who wheeze only when they have a respiratory tract infection (regardless of whether or not they’ve been diagnosed with asthma), the new guidelines recommend a short course of inhaled corticosteroids plus a rescue inhaler as needed. This can prevent worsening of breathing problems and forestall the need for corticosteroid pills.
Most asthma medications are breathed in through the use of an inhaler or nebulizer. There are two main types of inhalers; a metered dose inhaler (MDI), which uses a pressurized medicine-filled canister, and a dry powder inhaler (DPI), containing medicine in powdered form. A nebulizer uses a mask and delivers medication as a mist. It’s important to learn the different techniques for using these devices to ensure the medicine reaches your lungs.
There are few evidence-backed natural remedies for asthma, particularly if your case is severe. But lifestyle changes, like controlling stress, and some complementary therapies, like acupuncture, may help manage symptoms.
If your asthma is triggered by allergies, doing all you can to reduce your exposure to your trigger allergen — such as pollen, pet dander, dust mites, or cockroaches and rodents — may help. Allergy shots may help, too.
Doctors aren’t sure why asthma develops in the first place. The condition seems to stem from a mixture of genetic and environmental factors. That said, there are established risk factors for asthma. Avoiding them may lower your risk for developing the disease.
Breathing in air pollution and airborne allergens, irritants, or toxins can raise a person’s risk for developing asthma. It’s possible that avoiding airborne pollens, mold, chemicals, and traffic-related pollution may lower your risk of developing asthma in the future.
Obesity is also a major risk factor for asthma. Again, doctors aren’t sure exactly how obesity contributes to the development of asthma. Research from 2020 found that obesity promotes systemic inflammation, which could contribute to asthma. But more research is needed to firm up these links. Regardless, maintaining a healthy weight through diet and exercise can reduce your risk of developing asthma.
If you already have asthma and you’re hoping to prevent symptoms or flare-ups, there are a number of effective ways to go about this:
Follow your doctor’s instructions when it comes to taking your medication and avoiding your asthma triggers.
Get vaccinated. Viruses and infections can trigger flare-ups. You can lower your odds of developing one of these triggers by getting your seasonal flu shot and other scheduled vaccinations.
Monitor your asthma. Keeping tabs on your condition using a peak airflow meter can help you spot and head off impending flare-ups.
Keep an eye out for warning signs. A cough or frequent inhaler use are two signs that a bad flare-up is in the cards. Recognizing these sorts of red flags can help you take steps to prevent a bad attack.
For most people with asthma, using medications (like inhaled corticosteroids) and making certain lifestyle changes (like quitting smoking and maintaining a healthy weight) will allow them to manage their symptoms and avoid most short- and long-term complications.
But poorly managed or poorly treated asthma can result in additional problems. In the short-term those problems can include severe asthma attacks, disruption to normal activities, and increased risk of pneumonia and other lung infections. Farther down the line, problems can include permanent airway damage, mental health problems, weight gain, and increased risk of other chronic illnesses.
In 2020, more than 25 million people in the United States — or 7.8 percent of the population — had asthma, according to the Centers for Disease Control and Prevention (CDC).
More than 21 million of these people were adults age 18 or older.
About 41 percent of people with asthma reported having at least one asthma attack in 2020.
In 2020, asthma attacks resulted in about 1.2 million emergency room visits and 4,145 deaths in the United States.
On a global scale, about 262 million people have asthma, according to the World Health Organization.
Though asthma can affect people of all races and backgrounds, in the United States asthma is more likely to affect racial and ethnic minority groups, and outcomes are worse for these individuals. Children and adults who are Black, Hispanic (particularly people of Puerto Rican descent), and of Indigenous descent develop asthma more often, experience more severe and life-threatening asthma-attack emergencies, and have higher asthma-related death rates than white people and other racial and ethnic groups in America.
The causes driving these disparities are multifactorial.
One study from 2019 showed that Black children, teens, and adults with asthma were twice as likely as white Americans with asthma to visit the emergency room for an asthma emergency, owing to socioeconomic differences that made access to healthcare and asthma treatments more difficult for Black families.
Until recently there has been a lack of research into the biology and genetics of asthma in Black, Indigenous, and People of Color (BIPOC) groups, which has led to widespread one-size-fits all asthma treatment. For example, a study from 2018 found that albuterol, a widely used asthma drug that opens air passages, is significantly less effective in people of African descent than in people of other racial backgrounds.
And a 2020 report from the Asthma and Allergy Foundation of America (AAFA) — a comprehensive overview that looked closely at 15 years of national data about asthma cases, severity, and deaths — concluded that systemic racism, discriminatory housing policies, and environmental injustice also all contribute to these disparities in asthma prevalence and outcomes.
“Poverty, exposure to pollution, and limited access to medical care play a big role in racial disparities in asthma,” says Kenneth Mendez, AAFA’s president and CEO.
“These factors are interrelated and intergenerational,” he explains. Discriminatory housing policies, for example, have caused long-lasting residential segregation, in which poverty is concentrated in Black and Hispanic communities, which then perpetuates a cycle of limited access to education, employment, and quality healthcare services, he says. This residential segregation is also responsible for the disproportionate proximity of minority populations to sources of pollution, such as industrial centers, major roadways, oil and gas refineries, distribution hubs, and traffic-related pollution, which can put people at higher risk for asthma and having worse outcomes, Mendez explains.
AAFA’s report found that while rates of developing and dying from asthma declined in many BIPOC communities in the past decade, enormous disparities persist that need immediate attention from healthcare practitioners, researchers, and the American healthcare system. The AAFA report uses federal health data from several sources, including the National Vital Statistics System, National Health Interview Survey, National Hospital Discharge Survey, and others. The data comes from the CDC and from the U.S. Department of Health and Human Services. The findings include:
While the asthma rate among white Americans is about 7.6 percent, according to the AAFA report, it’s 10.6 percent among Blacks and 14.9 percent among Puerto Ricans — the highest rate among all racial and ethnic groups.
The number of asthma deaths per one million people is highest for Black Americans, at 23.9, followed by Puerto Ricans at 21.8, Hispanic Americans at 8.4 and white Americans at 7.4.
Emergency-room visits for asthma — a sign of asthma that’s not well-controlled — were five times higher for Black Americans compared with white Americans in 2017. The rate was 164.3 ER visits per 10,000 people for Black Americans, compared with 33.9 for white Americans. According to the U.S. Department of Health and Human Services Office of Minority Health, Hispanic Americans are twice as likely to visit the ER for asthma compared with non-Hispanic white Americans.
There’s little data on asthma’s effects in indigenous communities in the United States, but the AAFA report states that “tribal nations have among the highest rates of asthma prevalence, morbidity, and mortality.”
Asthma can be associated with several other conditions and health problems. In some cases, asthma can increase the likelihood of certain illnesses, like:
Bronchitis
Pneumonia
Additionally, there are some illnesses and health conditions that appear to be linked to asthma in that people with one are more likely to have the other, like:
