Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 11/12/2020
Asthma is a long-term disease that affects the bronchial tubes — the airways that help air flow in and out of your lungs.
If you have asthma, these airways may become inflamed and narrowed at certain points in time, causing you to experience symptoms such as breathlessness, wheezing, a tightening feeling in your chest and coughing.
The symptoms of asthma can vary widely in severity from person to person. Some people may only notice mild asthma symptoms every now and then, while others may have severe, chronic asthma that’s noticeable every day.
Asthma is a common disease in children and often develops during childhood, but it can affect people of all ages. According to Centers for Disease Control and Prevention data, more than 24 million American children and adults are currently affected by asthma.
A diverse range of factors may play a role in asthma, including your genetics and your level of exposure to certain irritants and allergens in the environment.
While there’s no cure for asthma, there are treatments available that can help you to keep your asthma symptoms under control.
Below, we’ve explained what asthma is, as well as the symptoms you may experience if you’re asthmatic. We’ve also looked at the factors that may contribute to asthma, from generics to the environmental factors that can cause forms of asthma such as occupational asthma.
Finally, we’ve discussed the treatments that you can use to control your asthma symptoms, as well as lifestyle changes you may be able to implement to reduce your risk of dealing with the symptoms of asthma in the future.
Asthma is a disease that affects the airways that allow air to flow in and out of your lungs, called the bronchial tubes.
In a person without asthma, the bronchial tubes function normally, allowing air to flow in and out from the lungs. In a person with asthma, the bronchial tubes are inflamed and swollen, making it harder for air to flow to and from the lungs when you breathe.
Asthma isn’t the only disease that causes the bronchial tubes to become inflamed. For example, some infections, such as acute bronchitis, also cause the bronchial tubes to temporarily become inflamed and make breathing difficult.
The difference is that while most other diseases that affect the bronchial tubes cause temporary symptoms, asthma can cause permanent inflammation.
Many people with asthma don’t experience symptoms from day to day. However, their airways may suddenly become swollen and tight when they’re exposed to an asthma trigger, such as a moldy or damp environment, a certain type of animal or polluted air.
Asthma can cause a range of symptoms related to your airways. The symptoms of asthma can vary hugely in severity. For some people, asthma causes mild symptoms that are fairly easy to control.
If you have mild asthma, you may be able to live a normal life with only mild symptoms that are uncomfortable but tolerable in most situations.
For others, it can cause debilitating, potentially life-threatening symptoms. If you have severe asthma, seemingly “simple” things such as spending time outdoors in certain seasons, working out or being exposed to pollution may trigger an asthma attack.
Everyone diagnosed with asthma needs an asthma action plan develop in conjunction with your healthcare provider.
Common signs and symptoms of asthma include:
Coughing. People with asthma may cough often, especially early in the morning or late at night. This happens when your body is trying to remove whatever it thinks is causing your lungs to feel irritated and inflamed.This is one of the most common signs of asthma.
Shortness of breath. If you have asthma, you might often find yourself short of breath, including in situations where non-affected people can breathe normally.
Wheezing. When you breathe in or out, you may notice a high-pitched whistling sound referred to as wheezing. Wheezing is usually easier to hear when you exhale (breathe out). This is the one of the most common symptoms of asthma.
Tightness in the chest. People with asthma often experience a feeling of tightness that affects the chest. You might feel like there’s a heavy weight sitting on top of your chest and causing extra pressure.
Difficulty sleeping. If you have asthma, you may find it difficult to sleep due to one or several of the symptoms above, such as coughing or wheezing.
Not everyone with asthma experiences all of these symptoms. You may only experience one or two of the symptoms listed above when you’re exposed to a certain type of trigger, but still have asthma.
If you have one or more of the symptoms listed above and think that you may have asthma, it’s important to talk to your healthcare provider. You can also consult with a primary care provider online and, if appropriate, receive medication to help you manage your asthma symptoms.
For many people, asthma symptoms appear suddenly during flare-ups, or asthma attacks. For example, a person with asthma may experience few or no symptoms, then quickly experience severe asthma symptoms after exposure to a specific allergen or irritant.
We’ve explained more about asthma attacks and the factors that can trigger them further down this page.
Currently, experts aren’t yet aware of the exact factors that cause asthma. However, modern research indicates that asthma is usually caused by an overly aggressive immune response to certain irritants or allergens in the lungs.
Many diseases are linked to the body’s immune response to certain substances. For example, some people experience allergic immune system reactions after eating certain foods or using certain types of medication.
When your body detects an infection or allergen, it responds by mobilizing your immune system to clear the intruder away. Normally, this is a good thing. For example, your immune system is a vital tool for getting rid of bacterial infections and viruses.
Part of the immune system’s response to injury and infection is inflammation. When your body’s tissue is damaged by a harmful substance, the damaged cells release chemicals that cause the area to become inflamed and swollen.
While this process can be uncomfortable, it helps to isolate the dangerous substance from your tissue, allowing the white blood cells of your immune system to respond to the threat and keep you healthy.
Every person is biologically unique, and no two people have identical immune systems. When one person breathes in a certain allergen, their immune system may only have a mild reaction that causes little or no inflammation.
If a different person comes into contact with the same allergen, the immune system may have an extreme reaction, causing significant inflammation and swelling of the airways.
Research suggests that asthma could be linked to immune system reactions that occur during childhood. A variety of factors may affect this immune response, including both genetics and factors in a person’s environment.
Although asthma usually develops in childhood, it can also develop in adults. When asthma is something that develops after childhood or adolescence, it’s generally referred to as late-onset or adult-onset asthma.
Certain factors could make you more at risk of developing asthma than other people. These can range from your genes to factors related to your occupation or lifestyle, such as your workplace or the area in which you live.
Experts believe that genetics may play a major role in the development of asthma. More than 100 genes are believed to be linked with allergic asthma, with many of these genes associated with airway function and the body’s immune response.
However, the relationship between specific genes and asthma is complex, with more research necessary before we can draw a direct relationship between certain genes and asthma risk.
People with relatives who have asthma may have a higher risk of developing asthma, as there is evidence that asthma may be passed down in families. Research shows that children with parents who have asthma (in particular, an asthmatic mother) have an elevated risk.
Your ethnicity may also affect your risk of developing asthma. For example, people of Puerto Rican or African descent have an elevated risk of developing asthma compared to people of other ethnicities.
Certain factors in your environment may affect your risk of developing asthma, both as a child and as an adult. In children, these may include:
Exposure to environmental microbes. Certain microbes, such as bacteria, viruses or fungi, may play a role in the development of the immune system and affect a child’s risk of developing asthma.
Exposure to tobacco smoke. Smoke from cigarettes and other tobacco products may increase a child’s risk of developing asthma.
Research shows that smoking during pregnancy may also contribute to a higher risk of asthma for children. Smoking also contributes to numerous other respiratory illnesses in children, such as bronchitis and pneumonia.
Exposure to air pollution. Air pollution from traffic, industrial facilities or other sources may contribute to the development of asthma children.
Respiratory infections. Developing certain respiratory infections may increase a child’s risk of developing asthma.
In adults, environmental factors that may contribute to asthma include:
Exposure to chemicals, fumes and dusts. Some chemical irritants and dusts may be linked to a form of asthma called occupational asthma.
People in industries such as baking, drug and/or chemical manufacturing, farming, grain elevator operation, laboratory work, metal work, milling, plastics and woodwork have an elevated risk of developing this form of asthma.
Exposure to air pollution. Like in children, exposure to air pollution may contribute to an increased risk of developing asthma in adults.
Obesity. Being obese may increase your risk of developing asthma. Obesity may also contribute to more severe, noticeable asthma symptoms.
Other allergies. People with other allergies, such as food, dust or pollen allergies, may have an elevated risk of developing asthma. In particular, people with several allergies have a significantly increased risk of developing asthma.
If you’re exposed to an allergen or other environmental asthma trigger, your asthma symptoms might suddenly flare up. This is known as an asthma attack. Asthma attacks can develop slowly or come on rapidly and, for some people, can cause severe, life-threatening symptoms.
During an asthma attack, you may experience coughing, difficulty breathing and a strong feeling of tightness in your chest. Your bronchial tubes may constrict so much that no matter how hard you try, taking a normal breath can feel extremely difficult.
Asthma attacks can vary in duration and severity. While a mild asthma attack may only go on for a few minutes, severe asthma attacks can cause symptoms that last for hours. In some cases, an asthma attack may continue over several days.
A variety of different substances can trigger asthma attacks, including natural allergens that are released from plants, illnesses and certain man-made substances. Common triggers for asthma attacks include:
Pollen, mold and spores. Pollen, mold and airborne spores are common allergens that can trigger asthma symptoms. This can be a particular problem if you live in a city with a high pollen count, or in a damp environment where mold can grow easily.
Dust mites. These microscopic bugs, which often live in bedding, carpets and furniture, can be a common asthma trigger. Dust mites tend to multiply in environments that are warm and humid.
Pests. Many household pests, such as mice, rats and cockroaches, can trigger asthma symptoms. These pests are often drawn to water and food sources inside your home, such as dirty dishes, crumbs and discarded food containers.
Pet dander. Dander, the small particles of skin that are shed from furry animals, are a common asthma trigger. Contrary to popular belief, pet fur isn’t an asthma trigger and trimming a pet’s fur will generally not provide relief from symptoms.
Cleaning products. Certain cleaning products, such as some disinfectants, can trigger asthma. In addition to cleaning products, products containing fragrances are potential asthma triggers.
Tobacco smoke. Smoke from cigarettes, cigars and other tobacco products can trigger asthma symptoms for many people. This includes second-hand smoke from people in your household or people that smoke close to you in public places.
Air pollution. Some forms of air pollution, such as pollution from cars, industrial facilities and fires, can trigger asthma. In addition to outside air pollution, burning particles from home fireplaces may also trigger asthma symptoms for some people.
Illnesses. Some illnesses and health conditions, particularly illnesses related to colds, influenza (flu), sinus infections, gastroesophageal reflux disease and human respiratory syncytial virus (RSV), may trigger asthma symptoms.
Some asthma triggers are behavioral instead of physical. For example, some people get asthma symptoms while exercising because of the shortness of breath caused by aerobic exercise. This is referred to as exercise-induced bronchoconstriction, or EIB.
Other people may get asthma symptoms due to laughter. For example, a small study from 2005 found that 56 percent of people affected by asthma get laughter-induced asthma (LIA), a type of asthma that may be triggered by laughter-related breathing patterns.
Because asthma can vary in severity, there’s no one-size-fits-all treatment for every person with asthma. Instead, your healthcare provider will recommend a suitable treatment for you based on the type and severity of asthma symptoms you experience, as well as your asthma triggers.
Asthma is typically treated using medication. There are two main types of asthma medications that you may be prescribed to control your symptoms:
Quick relief medications. Also known as short-term asthma medications, these work by preventing or controlling asthma symptoms as they occur.
Control medications. Also known as long-term asthma medications, these are taken regularly to help you have fewer and less severe asthma symptoms.
Quick relief medications are usually prescribed to treat mild asthma. You may be prescribed a medication of this type if you only experience asthma during demanding physical activity, such as when you exercise.
One of the most common quick relief medications for asthma is the rescue inhaler. These are also known as “metered-dose” inhalers, or simply as asthma inhalers. They work by releasing medication that relaxes the muscles around your airways to make breathing easier.
The medications used in rescue inhalers are referred to as inhaled short-acting beta2-agonists, or SABAs. SABAs used to treat asthma include salbutamol (also referred to as albuterol, and sold as Ventolin®) and levosalbutamol (also referred to as levalbuterol).
These medications are often effective, but they can cause side effects such as rapid heartbeat and tremors.
They’re also not intended for constant use. If you have asthma and you use your rescue inhaler more than two times per week, your healthcare provider may recommend using a longer-acting form of medication to control your symptoms.
Some asthma inhalers contain corticosteroids such as prednisone. These are intended for use as-needed during asthma attacks. However, these medications can cause side effects when used over the long term and should be used cautiously and with guidance of your healthcare provider.
Finally, some asthma inhalers contain medications called short-acting anticholinergics. These are intended for short-term relief of asthma and may be prescribed for people who experience side effects from inhalers containing salbutamol or levosalbutamol.
Control medications are used to prevent and manage asthma symptoms in the long term. Like quick relief medications, they work by reducing inflammation and preventing your airways from becoming overly narrow.
Unlike quick relief medications, control medications are designed to work constantly. If you’re prescribed a medication of this type, you’ll need to take it daily in order for it to be effective at preventing asthma.
Several long-term control medications are available for asthma. They include:
Inhaled long-acting beta2-agonists (LABAs). Like short-acting beta2-agonists, these work by releasing medication that relaxes your airway muscles and keeps your airways open. However, they remain active for a significantly longer period of time.LABAs should never be prescribed as the sole therapy for asthma
Corticosteroids. These help to lower inflammation by limiting your immune response to asthma triggers. Your healthcare provider may prescribe corticosteroids in oral form, or in the form of an inhaler. Some inhalers contain corticosteroids and LABAs.
Biologic therapy medications. These medications contain cells from living organisms that are modified to target the antibodies or inflammatory molecules that cause asthma symptoms.
Biologic medications don’t come in inhaler or tablet form — instead, you’ll need to have them administered by injection in your healthcare provider’s office. Most biologics will remain effective for two to eight weeks, depending on type, after each injection.
Leukotriene modifiers. These reduce inflammation and stop asthma symptoms from occurring. Leukotriene modifiers come in pill form and may be taken with other asthma medications such as corticosteroids.
Subcutaneous immunotherapy (SCIT). Also known as allergy shots, SCIT involves injecting small amounts of asthma-causing allergens into the skin. This may help to relieve the allergic reactions that can contribute to asthma symptoms.
Mast cell stabilizers. These medications prevent the release of chemical signals that trigger inflammation from mast cells — cells found in the airways that play a key role in causing asthma symptoms.
If you experience a severe asthma attack that doesn’t improve with medication, you should seek emergency medical care.
Call 911 or go to your hospital’s emergency department if your asthma symptoms become more severe even with the use of medication, you feel drowsy, or your peak expiratory flow falls to 50 percent of your personal best or less.
Although there’s no cure for asthma, using your medication and making small, simple changes to your lifestyle can make living with asthma significantly easier. Try the following tips to stay in control of your asthma and prevent asthma attacks from occurring:
Identify your asthma triggers. Asthma triggers can differ from one person to another, making it important to identify the specific factors that are responsible for your asthma symptoms.
Once you know about the things that trigger your asthma, take action to avoid irritants, pets and situations that may cause you to experience an asthma attack.
Keep your home clean and dust-free. Dust mites and mold can thrive in homes that are unclean. Likewise, pests such as cockroaches and rodents can thrive on leftovers, dirty plates and other sources of food and water that are left out in the open.
If mold or pests are asthma triggers for you, make sure to keep your home sanitary and free of allergens that could cause your asthma symptoms to worsen.
Create an asthma action plan. Working with your healthcare provider, create an action plan for dealing with your asthma. An action plan can help you to stay in control of your asthma by using color-coded zones based on your symptoms.
You can find out more about asthma action plans at the CDC website. The plan uses an easy-to-follow green, yellow and red system to classify your symptoms and help you take effective action when you experience an asthma attack.
Keep in regular contact with your healthcare provider. Finally, keep in contact with your healthcare provider to let them know how you’re doing. If your symptoms improve or worsen, make sure that you let them know as soon as possible.
Asthma can vary in severity over time. Your healthcare provider will check your airway and lung function over time to see how you’re progressing and, if needed, adjust your treatment to suit your needs.
Asthma is a common disease that affects tens of millions of Americans of all ages. It can vary hugely in severity, with some people only experiencing mild symptoms and others affected by severe, chronic asthma attacks.
While asthma unfortunately isn’t curable, a range of effective treatments are available to help you keep your asthma symptoms under control and enjoy a high quality of life.
If you think that you may have asthma, talk to your healthcare provider. You can also talk to a primary care provider online to receive personalized advice and, if appropriate, medication to treat your asthma symptoms.
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