Asthma diagnosis: procedure and tests

What can I expect when I visit the doctor?

What are the symptoms of asthma?

Bronchial asthma is one of the most common chronic respiratory diseases. Characteristic symptoms such as shortness of breath and tightness in the chest can be a sign of asthma, but not necessarily. In fact, bronchial asthma can manifest itself differently in each individual case.

Above all, it is important to discuss your suspected asthma with a specialist as soon as possible, if only to avoid the risk of constant aggravation. The earlier you are diagnosed with asthma, the easier it is to control your asthma with medication. Especially if your symptoms persist and do not improve with cough suppressant therapy, medical attention should no longer be delayed.

Main methods and procedures for diagnosing asthma

The diagnosis of asthma is based on a detailed history taken by your doctor to determine your medical history. This is often done by your family doctor. In the case of allergic asthma, the first interview may also take place with an allergist who is treating you for your allergic symptoms. It is also possible to go to a pulmonologist. He or she has the equipment to perform more thorough airway examinations.

Consult your doctor if you have any suspicions

When you talk to your doctor, you should give information about the problems you have experienced so far and about the circumstances in which your symptoms appear, for example certain situations, times of day or seasons. The alternation of more or less severe attacks and phases with little or no symptoms is not atypical in the course of an asthma disease. It is therefore equally important to get as accurate a picture as possible of the symptoms, which may not be acutely detectable at the time of your visit to the doctor.

Older patients tend to be less affected by asthma. With age, it is more likely that the lungs are damaged by other factors such as environmental pollutants or smoking. Nevertheless, bronchial asthma can occur at any age. Even in older patients, it should be investigated as a possible cause of the corresponding symptoms.

The history is followed by diagnostic procedures to clarify and distinguish the symptoms from other diseases. As part of the physical examination, auscultation – listening carefully with a stethoscope – plays a central role. Experienced physicians can draw conclusions about the type and extent of many airway diseases from the sounds of breathing. In the case of bronchial asthma, however, the extent of possible auscultation phenomena does not correlate with the degree of airway narrowing. Between asthma attacks, the physical examination may be completely imperceptible. In the case of existing narrowing, dry sounds such as wheezing, whistling and/or buzzing may appear on exhalation.

Can an allergy be the cause of my asthma?

A large proportion of asthma diseases are caused by allergies, especially in children and young adults. Mixed forms of allergic and non-allergic asthma are also common. It is therefore important to check whether you are allergic. To do this, specific allergy tests are performed, which can be classified as follows:

  • Skin test
  • provocation tests
  • blood tests

The prick test is a standard procedure often used. Different allergens are introduced directly into the upper layer of the skin with a small prick. In case of an allergic reaction, papules or redness appear on the affected areas. If the skin test is not clear, further provocation tests can be performed on organs such as the nose, eyes and bronchi. Blood tests, on the other hand, are performed in a laboratory. Here, the level of total IgE (IgE = immunoglobulin E) in the blood is measured, as well as the allergen-specific IgE antibodies. In case of uncertain results, additional examinations such as the determination of inflammation markers or cell tests can also be carried out by means of blood tests.

Lung function test – essential for the diagnosis of asthma

The pulmonary function test plays a central role in the diagnosis of asthma. It allows to confirm the diagnostic results by objective measurements. The data obtained during a lung function test give important indications about the severity of the asthma disease. Objectively measurable data are important because asthma disease progresses in attacks, and the essential symptoms are not always visible at the time of the medical consultation. While questioning by your doctor can help, it provides limited information, especially because patients’ perception of symptoms varies. Many people cannot assess the true severity of their asthma.

This is possible with a spirometric lung function test. It measures lung and breathing volumes and airflow velocities and records them. The data provides important results for assessing lung function and capacity.

Pulmonary function test

During the pulmonary function test, you breathe through a mouthpiece through what is called a spirometer and perform certain breathing maneuvers under the direction of the doctor. The one-second breathing capacity is a particularly telling index for asthma patients. It shows how much air you can breathe out in one second. The narrower your airway, the less air you can breathe out in one second.

Peak flow measurement is also an important parameter in the diagnosis of asthma: it allows you to determine the maximum speed of the air that leaves the lungs when you exhale. This method can be done at home with small self-testing devices. Lung function tests are not only important for the diagnosis of asthma. Regular measurements help to monitor the course of the disease.

In order to exclude other airway diseases, a diagnostic imaging procedure can also be helpful in the initial diagnosis of bronchial asthma. A two-plane chest x-ray has proven to be effective. Other examination methods that can be used to diagnose asthma include blood gas analysis and sputum examination.

If asthma is suspected, it is important to make a diagnosis as soon as possible. This is the only way to avoid a worsening of your disease. A thorough interview about your health and an examination of your chest cavity are usually the basis of the diagnosis. In order to confirm the diagnosis and to monitor the course of the disease, various pulmonary function tests are also carried out on the basis of objectively measurable data. In order to be able to identify possible allergies as a cause of asthma, allergy tests are also carried out if necessary. X-rays as well as sputum or blood gas analyses can also be used to rule out other diseases.

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