A chest X-ray can be an important screening tool for people with asthma, but an X-ray alone is not enough to diagnose the condition.

A person lying down in an X-ray machineShare on Pinterest
Urs Siedentop & Co/Stocksy

Approximately 25 million adults in the United States (U.S.) are living with asthma. It is the most common chronic disease in children.

The first step in asthma treatment is an accurate diagnosis. Doctors use a range of tests to check for asthma symptoms, including blood tests and lung function tests.

A chest X-ray can also be helpful for people who have severe asthma or live with another condition alongside asthma.

Keep reading to learn more about the diagnosis and treatment of asthma and how and when an asthma X-ray can help.

About 5 million children in the U.S. currently have asthma. In adults, the condition is more prevalent among females than males, but more boys than girls receive a diagnosis during childhood.

Many people with asthma may not know that they have the condition, especially if they experience only mild symptoms. They may mistake these symptoms for those of another condition.

Some of the most common asthma symptoms include:


There is no known cause of asthma. However, a person’s genetic background and environment can play a role in the development of the condition.

Some people experience asthma as part of an allergic reaction. Others may notice that their symptoms occur in response to triggers such as temperature changes or certain household cleaners.

People with asthma may also have a slightly increased risk of illness from COVID-19, so they should receive the COVID-19 vaccination.

Asthma exacerbations can also result from respiratory conditions, such as the flu and pneumonia. A person should receive seasonal vaccinations to help prevent any complications.

Learn more about the flu shot.


Healthcare professionals use various diagnostic tests to detect asthma. These may include a physical exam and tests that measure lung function. Doctors may also test for allergies through skin tests or blood analysis.

Early diagnosis and treatment are essential for managing asthma symptoms. Some asthma attacks may be brief and mild. Other attacks can last for a long time and cause serious harm if a person does not get treatment.

Learn more by visiting our asthma and allergies hub.

Generally, doctors do not use chest X-rays to diagnose asthma. Instead, they may use this test to rule out conditions other than asthma.

Other conditions may cause similar symptoms to asthma. For example, an individual may have something stuck in their airways. An X-ray can identify any foreign objects, and it can also detect the signs of certain heart and lung conditions.

People experiencing severe asthma may also have an X-ray to test for additional diseases or damage to the lungs.

A chest X-ray can detect many potential health concerns, including:

A chest X-ray uses a special type of low dose radiation to create pictures of the chest’s interior. This type of X-ray allows a healthcare professional to see various parts of the body, including the:

  • heart
  • lungs
  • aorta
  • bones in the chest

No specific preparation is necessary for a chest X-ray. Before the exam, an individual will exchange their clothes for a medical gown and take off any metallic jewelry or other accessories.

During the exam, the individual will stand near the X-ray machine and hold still. A technician will then carry out the X-ray, which generally does not take more than a few minutes.

Finally, a radiologist will examine the results and pass them along to other doctors or specialists as necessary.

If a person undergoes an X-ray when pregnant, there is a risk that it will affect the fetus, leading to congenital abnormalities. Anyone who is pregnant, or suspects that they might be, should tell the doctor before undergoing an X-ray.

There is also a slight possibility that the radiation that the imaging tests use will increase a person’s cancer risk. However, this is not overly likely given that the tests use low doses.

Anyone concerned about radiation should speak with a doctor to learn more about the specific risks they may face.

There are many different diagnostic tests for asthma, ranging from standard physical exams to imaging tests.

Blood tests

Most asthma specialists carry out blood tests as part of a routine asthma screening. These tests can detect environmental allergies, elevated levels of white blood cells called eosinophils, and lowered vitamin D levels. They can also determine whether any organs are not functioning correctly.

Identifying one of these health issues could rule out an asthma diagnosis.

Sputum induction tests

Sputum is a combination of saliva and mucus that is present in the lungs. During a sputum induction test, a clinician will take a sample of sputum from the person’s lungs.

They will then send the sample to a laboratory for further testing to determine the cause of lung inflammation and the best treatments to pursue.

Chest CT scan

A chest CT scan takes 2D pictures of different chest cross-sections. A computer arranges these images for a healthcare professional to review.

Doctors often use this test as part of an asthma diagnosis, as it can provide evidence of the presence of asthma. It can also rule out asthma by identifying other conditions, such as bronchiectasis, which causes symptoms that may mimic asthma symptoms.

Beta-agonist and anticholinergic inhalers are useful for the immediate relief of asthma symptoms. These treatments enlarge the passageways to the lungs.

Both treatments are examples of bronchodilators that can control immediate distress by making it easier for air to come into and out of the lungs.

People may take long-term medications daily that work to keep the symptoms of asthma in check over time. These include:

People who experience asthma as part of an allergic response may also go through immunotherapy.

This treatment includes receiving regular allergy shots or taking immunotherapy pills to help reduce the frequency and severity of asthma attacks.

Learn more about asthma medications.

Most people with asthma can manage their symptoms with a combination of medication and lifestyle adjustments.

Making lifestyle adjustments can involve taking steps to avoid known triggers, which may include:

  • emotional irritability or stress
  • aspirin
  • exercise
  • breathing cold air
  • cigarette smoke
  • certain foods that trigger an allergic response

People who are unsure what may be triggering their symptoms can seek advice from a doctor on making lifestyle modifications to help them determine their triggers.

There is no single cure for asthma, but a range of treatments and techniques can keep the condition in check. The best way to determine what works is for each individual to work with a doctor to create an asthma action plan.

Learn more about controlling asthma symptoms.

Asthma is a common condition that affects many adults and children. Doctors use a variety of physical and imaging tests to diagnose asthma.

A chest X-ray may be helpful for identifying additional conditions that might be causing or exacerbating an individual’s symptoms. However, doctors cannot make an asthma diagnosis based on an X-ray alone.

People with asthma can manage the condition with medication and certain lifestyle adjustments, which can improve their quality of life.