This informational guide, part of PS's Condition Center [1], lays out the realities of this health concern: what it is, what it can look like, and strategies that medical experts say are proven to help. You should always consult your doctor regarding matters pertaining to your health and before starting any course of medical treatment.

Asthma is the most common chronic illness to affect children — and most don't outgrow it. Of the approximately 25 million people in the US with the breathing condition, more than 20 million are adults, according to 2021 data [2] from the Centers for Disease Control and Prevention (CDC). It's also possible to develop the condition, which is characterized by airway inflammation, in adulthood. And while more boys are affected by childhood asthma, in adulthood, the condition starts to affect more women, studies show [3]. Regardless of when you first develop symptoms, it's crucial to learn how to manage them effectively: more than 3,500 people die of asthma attacks each year. Ahead, a pulmonologist breaks down everything you need to know about asthma, including symptoms, causes, diagnosis, and treatment.

Experts Featured in This Article:

Russell Buhr [4], MD, is an assistant clinical professor in pulmonary and critical-care medicine at UCLA's David Geffen School of Medicine.

What Is Asthma?

"Asthma is a chronic (long-term) condition that affects the airways in the lungs," according to the National Heart, Lung, and Blood Institute [5]. "If you have asthma, the airways can become inflamed and narrowed at times. This makes it harder for air to flow out of your airways when you breathe out."

When you have asthma, the passages that carry air to the lungs can become severely swollen and inflamed, making it hard to breathe; this could result in an asthma attack. Attacks often hit at night or early in the morning. They can be caused by specific triggers, such as tobacco or wood smoke, air pollution, pets, mold, dust mites, or cockroaches. For some people, exercise can set off an attack. Triggers differ among people with asthma, so one of the most important things you can do is identify — and avoid — your particular triggers.

Asthma attacks can also be caused by infections that affect your lungs, including COVID-19 [6] or the flu [7]. "After a viral infection, some people develop postinfectious airway disease, which mimics asthma, but it resolves after a few months," says Russell Buhr, MD [8], assistant clinical professor in pulmonary and critical-care medicine at UCLA's David Geffen School of Medicine.

Asthma Symptoms

Symptoms of asthma can run the gamut and vary from person to person, per Dr. Buhr, but often include:

• Wheezing (you may notice a high-pitched whistling sound when you inhale or exhale)
• Breathlessness
• Coughing
• Feeling of tightness in your chest.

Causes of Asthma

It's not completely understood why asthma impacts some people over others, but experts have a few theories.

• Childhood exposures to allergens, which causes the airways to become sensitized and hyperreactive, could be a contributing factor, Dr. Buhr says. "Things like air pollution and dust can cause problems," he adds.
• Climate change leads to increased air pollution and can be another contributing factor, according to the Asthma and Allergy Foundation of America [9].
• There's also a hereditary component to asthma. If one of your parents had it, you may be more at risk [10].
• Gender and hormones may also play a role. Nearly 10 percent of adult women, compared to six percent of men, have asthma, per the CDC [11] — a gender disparity that may be explained, at least in part, by hormones. Men may get some protection from testosterone, which hinders an immune cell linked to asthma symptoms, like inflammation and mucus production in the lungs, according to a 2017 study [12] by researchers at Vanderbilt and Johns Hopkins universities.
• An exposure to household chemicals has also been linked to an increased risk of adult asthma [13].
• Race and ethnicity also play a role. Black Americans [14], Hispanic Americans [15], American Indians/Alaskan Natives [16], and Native Hawaiians/Pacific Islanders [17] are disproportionately affected by asthma, a disparity that is caused by a variety of factors, such as a lack of routine access to healthcare and asthma specialists, systemic racism, poverty, and exposure to air pollution and other potential environmental triggers.

How Is Asthma Diagnosed?

There's no single test for asthma. The condition is diagnosed [18] based on symptoms, Dr. Buhr says, and sometimes via lung-function tests (spirometry). So if you're wheezing or coughing at night [19], it's important to bring it up with your doctor so that you can come up with a treatment plan.

Treatments For Asthma

"The mainstay of treatment is inhaled steroids, which people take as needed," Dr. Buhr says. If you have exercise-induced asthma, for instance, you might take a puff before a workout to prevent problems. Others may need to use their inhalers more during allergy season if they're sensitive to pollen.

If inhaled steroids aren't enough to control your asthma, doctors may also prescribe injectable medications, known as biologic therapy, which block inflammation-causing molecules in your immune system.

Adhering to your asthma treatment plan is vital since poor asthma management can lead to airway remodeling, in which the lungs become scarred and no longer respond well to asthma medications. It can also put you at risk of a deadly asthma attack. "Asthma is controllable, but it's important to work with a doctor to make sure you're staying on top of your symptoms and getting the treatment you need," Dr. Buhr says.

Ginny Graves [20] is an award-winning writer in the San Francisco Bay Area whose work focuses on science, psychology, health, nature, and the human-animal bond.