What is asthma?
Asthma is a chronic lung disease marked by acute flare-ups of inflammation and swelling of the airways in the lungs. Asthma is one of the most common childhood diseases, but it also affects adults. According to the Centers for Disease Control and Prevention (CDC), more than 26 million adults and 6 million children (younger than 18) are living with asthma in the United States. Most new asthma cases are diagnosed before the person’s 7th birthday. The most common type is allergic asthma.
Asthma affects the bronchioles, small hollow passageways in the lungs, and the alveoli, which are attached to the bronchioles. The alveoli are tiny sac-like structures where oxygen is absorbed into the bloodstream.
During an asthma attack, the bronchioles and alveoli overreact to certain triggers and become inflamed, irritated and swollen. This hinders the flow of air into the lungs and causes wheezing, chest tightness, difficulty breathing, and coughing. The smooth muscles surrounding the airways react by tightening, further blocking airflow. Mucus production increases, further exacerbating breathing troubles.
Minor shortness of breath can be treated at home by following your treatment plan or at a doctor’s office. If you experience trouble breathing—with or without chest tightness or wheezing—after taking your medications according to your treatment plan, contact your healthcare professional. More severe asthma attacks can quickly progress from minor shortness of breath to a life-threatening situation.
What are the different types of asthma?
"Asthma" is a general term. There are several types of asthma, each with a different cause or trigger:
- Allergic asthma, or extrinsic asthma, is one of the most common types. It usually develops during childhood. Many different allergens can trigger allergic asthma.
- Exercise-induced asthma occurs only during periods of increased physical activity
- Eosinophilic asthma is a rare and severe type. It is associated with increased swelling within the respiratory system due to higher counts of eosinophils. Eosinophils are a type of white blood cells.
- Nocturnal asthma, or nighttime asthma, is a type that occurs primarily during sleep.
- Occupational asthma, or work-related asthma, is triggered by substances at the workplace. This includes chemicals, metal shavings, and dust, among others.
There are also other subtypes and classifications. This includes intrinsic (nonallergic) asthma, cough-variant asthma, obesity-related asthma, steroid-resistant asthma, and adult-onset asthma.
What are the symptoms of asthma?
Symptoms of asthma include shortness of breath, cough, chest tightness, and wheezing. Wheezing is a "whistling" noise that occurs while breathing. It can be heard through a stethoscope or, in certain cases, by the naked ear. Early signs of an asthma flare-up can be subtle and include restlessness, anxiety, and wheezing that cannot be heard by the naked ear. It may also be difficult to hear wheezing in extreme asthma flare-ups because the airways have become so narrow that there is not enough air moving through them to create a sound. Physicians are particularly concerned when patients are experiencing poor air movement through their lungs.
Common symptoms of asthma
You may experience asthma symptoms daily or just once in a while. At times any of these asthma symptoms can be severe:
- Anxiety and restlessness
- Breathing difficulty and shortness of breath
- Chest retractions
- Chest tightness
- Difficulty speaking
- Flared nostrils, especially in children
- Need to sit upright
- Pale skin
- Persistent cough or cough that is worse at night
- Rapid breathing (tachypnea) and rapid pulse (tachycardia)
Serious symptoms that might indicate a life-threatening condition
More severe asthma attacks can quickly progress from minor shortness of breath to a life-threatening situation. Symptoms that may indicate a serious or life-threatening condition that should be immediately evaluated in an emergency setting include:
What causes asthma?
The exact cause of asthma is not known, but it likely involves a combination of environmental and genetic factors, involving the genes related to the immune system or how the lungs and airways function.
When asthma is associated with allergies, the disease is referred to as allergic asthma or allergy-induced asthma. Allergic asthma can run in families, supporting the role of genetic factors. The underlying problem lies in a heightened immune response. The airways are very sensitive to allergens and the immune system sees the allergen as harmful and overreacts. The muscles around the airways tighten, and the tissues lining the airways swell and make extra mucus.
Substances that directly irritate the lining of the airways can also trigger asthma. Asthma caused by breathing irritating or toxic chemicals encountered on the job is called occupational asthma. Exercise-induced asthma is caused by rigorous physical activity.
Symptoms of asthma are due to an oversensitivity and overreaction of the lungs to certain triggers, resulting in inflammation and swelling of the airways.
Asthma triggers vary from person to person, as well as season to season, and can include:
- Air pollution
- Allergic reactions to allergens, such as pollen, dust, mold, animal dander, cockroaches, and dust mites
- Cold air
- Infections, including colds and sinusitis
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Respiratory infections
- Sulfites found in certain foods, such as beer, wine and seafood
- Tobacco smoke
What are the risk factors for asthma?
U.S. rates of asthma have been steadily rising, from about 3% of the population in 1980 to about 8% in 2016. Asthma rates are higher among African Americans (11.6%) than white Americans (8.3%) and Hispanic Americans 6.6%).
A number of factors are thought to increase your chances of developing asthma. Common risk factors include:
- Childhood exposure to caregivers with high emotional stress
- Exposure to irritating chemicals, air pollution, or secondhand smoke
- Family history of asthma, such as a parent or sibling
- Frequent colds or other respiratory infections, such as bronchitis, especially in children
- Low birth weight
- Medical history of allergies or eczema
- Overweight and obesity
- Prenatal exposure to poor diet or nutrition, and emotional stress in the mother
- Prenatal and postnatal exposure to tobacco smoke
- Working in occupations with exposure to chemicals, dust, fire, fumes, and many other damaging agents. (About 15% of severe asthma cases are due to occupational triggers.)
Reducing your risk of asthma
You may be able to lower your risk of asthma by:
- Maintaining a healthy weight
- Not smoking
- Removing irritants and potential allergens from your home, such as tobacco smoke
- Staying indoors with closed windows on high pollution days
- Wearing a special mask over your nose and mouth to prevent breathing in particulates and noxious fumes
If you have risk factors for asthma, talk with your doctor about ways to protect your respiratory health.
What are some conditions related to asthma?
Conditions with asthma or asthma-like symptoms include:
- Allergic bronchopulmonary aspergillosis (ABPA), an inflammatory reaction to the common mold Aspergillus
- Chronic cough syndrome, a cough lasting six weeks or longer, possibly due to more than one cause, such as a viral infection and allergies
- Churg-Strauss syndrome (CSS), also known as eosinophilic granulomatosis with polyarteritis (EGPA). CSS causes blood vessel inflammation in the lungs, skin, nerves and stomach.
- COPD (chronic obstructive pulmonary disease), characterized by lung inflammation and permanent lung damage that blocks airflow
How do doctors diagnose asthma?
The main methods for diagnosing asthma are:
- Patient health history, including symptoms, known allergies, current and past health problems, lifestyle habits, and environmental exposures
- Family medical history, including allergies, skin conditions, and respiratory diseases
- Physical exam, including evaluation of the lungs, nose, throat, ears, eyes and skin
- Lung function and breathing tests, including spirometry, peak expiratory flow, and bronchoprovocation testing
Other potential tests include chest X-rays, blood tests and allergy tests.
In children younger than 5 years old, a doctor may first prescribe an asthma medicine before ordering a breathing test. If symptoms improve, the child may have asthma.
How is asthma treated?
Although there is no cure for asthma, you can control it with regular medical care and by consistently following your treatment plan. Asthma treatment plans use a multifaceted approach and are individualized to the type and severity of your asthma.
In addition to medication, a treatment plan for asthma generally includes modifying your lifestyle to reduce your exposure to triggers, such as allergens, air pollution, and smoke. Your doctor may recommend allergy testing to identify possible allergic triggers of your asthma.
Medications to treat asthma include long-term control medications and quick-relief “rescue” medications. Most asthma drugs work by reducing airway inflammation (anti-inflammatories, such as corticosteroids) and/or by opening the airways (bronchodilators).
Long-term control asthma medications
Long-term control medications are inhaled or taken orally every day to control and prevent symptoms. Generally, the most effective long-term control medications are inhaled corticosteroids. Long-term control medications include:
- Immunomodulators: omalizumab (Xolair)
- Inhaled corticosteroids: budesonide (Pulmicort Flexhaler, Pulmicort Respules); flunisolide (Aerobid Aerosol); fluticasone propionate (Flovent HFA); triamcinolone acetonide (Azmacort Inhalation Aerosol)
- Leukotriene modifiers: montelukast (Singulair), zafirlukast (Accolate), zileuton (Zyflo CR)
- Long-acting beta agonists (bronchodilators): salmeterol (Serevent Diskus); formoterol (Foradil Aerolizer); albuterol sulfate (VoSpire ER Extended-Release Tablets)
- Methylxanthines: theophylline (Theo 24, Theochron, Elixophyllin, Uniphyl), dyphylline (Dilor)
- Combination medications: Advair Diskus, Symbicort
Quick-relief asthma medications
"Rescue" or quick-relief medications treat acute symptoms and are generally inhaled through a device called an inhaler. Rescue medications are used on the spot when a person feels a sudden onset of asthma symptoms. Fast-acting asthma medications include:
- Oral or intravenous corticosteroids: methylprednisolone
- Short-acting beta agonists (bronchodilators): albuterol sulfate (ProAir, Proventil, Ventolin, AccuNeb Inhalation solution); levalbuterol HCl (Xopenex); pirbuterol (Maxair)
- Combination medications: ipratropium bromide/albuterol sulfate (Combivent Inhalation Aerosol)
Many inhalers look alike but contain different quick-relief medications. Therefore it is very important not to share asthma medications.
Asthma action plan
Asthmatics should write an asthma action plan with help from their doctor. An asthma action plan contains information on how to manage your asthma under three different situations: When your asthma is controlled, flaring up, or an emergency. Your asthma action plan lists your:
- Asthma triggers and how to minimize exposure
- Medications and detailed instructions for how to take them and when, such as your daily asthma medicine and quick-relief medicine
- Peak flow meter readings, including what action to take depending on the reading. These are usually divided into green (controlled), yellow (asthma attack or worsening symptoms), and red (emergency).
- Emergency contact information
Keep a copy of your or your child’s asthma action plan at home and at work or school, respectively.
Additional treatments for asthma
Other types of care for asthma may be necessary in some cases. Treatment may include:
- Epinephrine (including the brand name Adrenalin) injections for life-threatening asthma attacks
- Intubation and ventilation (for exhaustion or respiratory arrest due to severe asthma)
- Supplemental oxygen
Alternative treatments for asthma
Some people with asthma explore alternative treatments, such as acupuncture or dietary supplements. If you decide to try alternative treatment, it should not replace your daily and quick-relief asthma medicine. Rather, it complements your existing treatment plan. Alternative treatments with some research support include:
- Breathing practices, such as Buteyko breathing and breathing during yoga and meditation
- Herbal remedies for asthma
Lifestyle changes for asthma
In addition to reducing your exposure to asthma triggers, you can also prevent or limit asthma attacks and asthma from allergies by:
- Avoiding cold air
- Avoiding or eliminating exposure to triggers, such as smoke, air pollution, animal dander, and dust
- Dehumidifying the air
- Eating a diet rich in fruits and vegetables
- Losing excess weight
- Quitting smoking today
- Reducing your stress levels
What are the potential complications of asthma?
Complications of untreated or poorly controlled asthma can be serious and even life-threatening. They include:
- Hypoxia (low levels of oxygen in the blood)
- Inability to participate normally in activities
- Inability to sleep well
- Permanent narrowing of breathing passages
- Respiratory arrest
How does asthma affect quality of life?
The harder it is to control asthma, the greater the impact on quality of life. The limits asthma imposes on social activities and obligations also plays a large role.
Asthma may result in:
- Asthma attacks and hospitalizations: 54% of children and 45% of adults with asthma report having asthma attacks.
- Economic hardship: Asthma treatment costs per person per year are about $3,266. This includes prescription drugs, doctor visits, and hospital stays. Nationally, the economic cost of asthma—medical costs plus lost productivity—is $82 billion.
- Increased healthcare visits: Recommendations include a checkup every six months for controlled asthma and more frequent visits for poorly controlled asthma.
- Limits in physical and social activities
- Missed school and work: The percentage of children missing school due to asthma is decreasing, but asthma-related missed school days is in the millions annually.
Does asthma shorten life expectancy?
Asthma is a chronic lung disease that can shorten life expectancy. Asthmatics with controlled asthma are more likely than people with uncontrolled asthma to live a normal, healthy life. Unfortunately, more than 60% of adults and 50% of children with asthma have uncontrolled asthma.
In the United States, 3,441 people, including 192 children died of asthma in 2018, the most recent year for which data are available, but the overall rate of asthma deaths is declining.
Well controlled asthma is a combination of symptom control with your treatment plan and maintaining a low risk of asthma attacks and medication side effects. Seeking care from an asthma specialist will increase your chances of controlling your asthma and reducing your risk of future problems related to your asthma.
More people each year and across the globe are developing asthma. However, increased awareness has led to earlier diagnosis and treatment. More treatment options have led to better symptom control and improved quality of life for millions of people with asthma.
May is National Asthma and Allergy Awareness Month.