In order to choose the right course of treatment, an accurate diagnosis is required. There are diseases that have specific symptoms, and in this case it is not difficult to determine the disease.

Bronchial asthma is not one of them, therefore, when a suspicion of a pathology of the respiratory tract arises, a thorough examination of the patient is required.

Modern diagnostics of asthma includes not only a visual examination of the patient, but also some instrumental methods that allow to identify the nature of the disease and determine the stage of its development.

Bronchial asthma

If a person is aware of how asthma is recognized and knows which doctor to turn to for help if breathing problems occur, it is often possible to avoid a serious illness. Asthma is a chronic disease of the respiratory system, in the development of which various cellular elements are involved.

The disease is characterized by an obstructive process in the bronchi, as a result of which their patency is impaired. The person begins to notice that breathing becomes hoarse and wheezing, shortness of breath, a feeling of fullness in the chest and a suffocating cough.

The importance of differential diagnosis in asthma

Asthma symptoms in an adult or child cannot be ignored. The most severe manifestation of the disease is status asthmaticus , a condition that can be fatal. The threat to life in this case is due to hypoxia and suffocation, which arose against the background of edema and spasm of the bronchi.   

It is also important to diagnose bronchial asthma in time because the quality of life of a sick person is deteriorating due to coughing fits and lack of air, and he needs urgent treatment. The first point to get rid of coughing fits is to see a doctor.

To date, there are numerous diagnostic criteria for bronchial asthma. It is not always easy to recognize bronchial asthma against the background of other diseases of the respiratory system, since the disease does not differ in specific signs, therefore, one cannot self-medicate.

The correct diagnosis determines how effective the selected treatment will be, how soon the disease will go into remission, and how long this period will last.

Taking anamnesis

For a doctor who examines a patient with bronchial asthma, a diagnosis based on the collection of anamnesis is necessary in order to choose the correct course of dealing with the disease.

The patient should tell the therapist:

  • what were the first symptoms of respiratory pathology, and after what disease they were found (whooping cough, measles, etc.);
  • at what age the suffocating cough began;
  • whether there were cases of bronchial asthma or allergies in the family;
  • what is the reason for the occurrence of an attack (stress, physical activity, contact with any substances, with animals or cold air, etc.);
  • how it is easier to cope with suffocation (is it convenient to lean on something, relaxing the shoulder girdle at this time);
  • what sounds are accompanied by breathing [M14] (in case of an asthmatic attack, wheezing is supplemented by wheezing); 
  • how spontaneously suffocation begins (is there a sore throat, a runny nose or itchy skin before this);
  • at what time of the day there is a lack of air more often;
  • Does taking bronchodilator drugs help relieve the attack?

Interviewing a patient and collecting anamnesis is not the most reliable, but very important method of differential diagnosis of the disease.

Together with the results of laboratory tests, it gives the doctor an almost complete picture of the disease.

Visual inspection

An attack of bronchial asthma can be similar to bronchitis – an acute inflammation of the mucous membrane lining the bronchi. Shortness of breath and cough, which the patient complains about, can appear with various diseases, therefore, a thorough examination is required.

If bronchial asthma is suspected in a patient with breathing disorders, diagnosis should include a physical examination. During a visual examination of the patient, a change in the shape of the chest is often noted.

This condition usually indicates the development of pulmonary emphysema. As a result of the strong expansion of the paired respiratory organ, the chest acquires a barrel-shaped shape.

The survey, as a rule, does not end with just one examination. An experienced doctor can judge the presence of a narrowing of the bronchial lumen by tapping and listening to the patient’s chest.

Auscultation and percussion

In the process of functioning, the internal organs of a person emit various sounds, which may indicate the presence of a particular pathology. A doctor who knows how to identify asthma uses auscultation as a diagnostic method.

Its essence lies in the fact that with the help of a stethoscope or phonendoscope the therapist listens to the patient’s chest, concluding that there is a pathology on the basis of sounds accompanying the work of the patient’s lungs and bronchi.

Percussion is another effective way to confirm asthma. This technique is the tapping of the studied area of ​​the body (if asthma is suspected, the chest is tapped).

Both methods have their own characteristics, for example:

  • at an early stage of the disease progression, percussion is ineffective, which cannot be said about a situation when the disease has become severe. With a protracted course of bronchial pathology, an emphysema change in the lungs may develop, and the doctor, with percussion, hears a sound resembling blows on a cardboard box;
  • in the process of auscultation, an experienced doctor is able to determine if the disease has gone into remission. In asthma in the acute stage, whistling sounds and wheezing are heard over the entire surface of the lungs. During the period of weakening of asthmatic symptoms, wheezing and whistling are detected only in the area of ​​the lower border of the shoulder blades (the patient must inhale vigorously).

Laboratory diagnostic methods

In order to determine the nature of respiratory pathology, various tests for asthma are also performed. These types of diagnostics include the identification of an allergic reaction provocateur (trigger).

An allergy test is carried out by scarification of the skin. Various allergens are applied to the damaged skin and the local reaction is monitored.

Diagnosis of bronchial asthma in adults is not complete without blood tests. If the asthmatic has an uncomplicated disease, the indicators usually fit within the normal range. If the disease progresses rapidly, there is a sharp jump in the level of hemoglobin in the person’s blood, which is responsible for the transfer of oxygen.

Failure of external respiration is also indicated by an increase in the number of erythrocytes. The rate of their sedimentation usually does not change (provided that the infectious process does not occur in the body).

In the presence of symptoms indicative of bronchial asthma, not only a complete blood count is required, but also its biochemical study. Venous blood is drawn on an empty stomach, otherwise the results will be distorted.

It is recommended to limit physical activity and avoid stress before testing. In a person with asthma, as a result of biochemical analysis, a large number of substances are found, formed in response to the influence of provoking factors.

In the blood of patients with atopic form of the disease, the content of E-immunoglobulin increases, while in asthmatics with a mixed form of the disease, the amount of protein G compounds increases.

The amount of immunoglobulins in the body of a person suffering from asthmatic attacks can also fit within the normal range. This situation is observed if the sensitivity is increased to only one allergen.

If you suspect a violation of the patency of the bronchi, a study of the gas composition of the blood can be carried out. This indicator reflects how severe the disease is.

An increase in the volume of carbon dioxide indicates that the disease is in an advanced stage and the patient needs oxygen inhalation.

Analyzes for bronchial asthma involve not only a blood test, but also the identification of specific inclusions in the patient’s sputum. Examining the biomaterial obtained from the bronchi, the laboratory assistant, as a rule, detects Kurshman’s casts (in the form of spirals), a number of eosinophils, as well as crystalline Charcot-Leiden inclusions.

Also, bronchial secretions can contain a large number of microbes and blood inclusions. Sputum in asthmatics differs from the usual, not only with microscopic examination. It has the following features:  

  • two-layer structure;
  • excessive viscosity;
  • thick consistency;
  • transparent color.

Among the laboratory methods for detecting asthma, there is also a stool analysis. The procedure is necessary to exclude helminthiasis, in which the frequency of asthmatic attacks increases due to poisoning of the body with toxins.

Instrumental diagnostics

Instrumental diagnostic methods for bronchial asthma are indispensable when it is required to make a diagnosis for both adults and very young patients. 

Modern diagnostic methods allow:

  • find out if there is a chance to get rid of bronchial obstruction;
  • study the ventilation capacity of the lungs and determine how well the organ copes with enriching the blood with oxygen;
  • find out if the narrowing of the lumen in the bronchi is due to the patient’s contact with triggers (irritants).

An examination plan for an adult or child may include provocative tests as a way to detect bronchial asthma. Informative tests include: 

  • inhalation with the addition of histamine;
  • exercise tests;
  • inhalation with dry cold air.

There are tests that can be carried out only under the strict supervision of a doctor and during a period when a person does not have seizures. For example, such studies include a test using methacholine, an M-anticholinergic stimulator that provokes bronchospasm in asthmatics.


Another method by which asthma is detected is radiography. X-ray examination is not required in every situation.

For example, it will not be superfluous if, during a visual examination, the doctor confirmed the development of emphysema. A visit to the X-ray room is also indicated if attacks of a suffocating cough continue in a person for a long time, and the selected treatment does not bring relief.

The doctor needs to exclude the presence of other pathologies of the respiratory system, which can be detected using X-ray examination methods.

In the early stages of asthma progression, radiography is not informative, since the lungs look almost the same as in a healthy person, so the doctor should prescribe other types of research.


Assessment of external respiratory function helps to identify asthma. Today, spirometry is the leading method for determining the rate at which air flows through the lungs. In addition, the use of a spirograph is informative in relation to the measurement of the total respiratory volume of the lungs.

The main criterion for the study is FEV1 (fixed expiratory volume per second). The result obtained in the course of a spirometric study allows one to judge the degree of bronchial patency. A healthy person exhales faster within 1 second, so his FEV1 will be higher.

The course of asthma is considered mild if the FEV1 criterion is at least 80% of the ideal value during spirometry. The result, which varies from 60 to 80%, is typical for a moderate course of the disease. An indicator that does not reach 60% indicates that the pathology is life threatening.

Peak flowmetry

Another method of differentiating asthma from other respiratory pathologies is peak flowmetry. The device required for research is called a peak flow meter and is a small apparatus that looks like a tube on which divisions are applied.

Each zone corresponds to a certain stage in the development of the disease. So, if the indicators of an asthmatic fit within the boundaries of the green zone, it is believed that the respiratory pathology is well controlled.

The result, located between the red and yellow divisions, signals the presence of an exacerbation. Noticing that the indicator is in the red zone, a person should immediately seek medical help.

The scale of the device is not unified, and the criteria for the norms are individual for each patient. In order to determine his normal values, the patient must repeat the forced exhalation several times, achieving the best result.

The peak flow meter is easy enough to use to make an asthma control test at home. The patient can independently measure the peak expiratory flow rate using the apparatus in the morning and evening hours.

It is recommended to write down the results of the tests performed in a diary, which the attending physician will later read.


A pneumotachograph is required to determine the total peak breathing volume and the maximum volumetric velocity. During the study, three test percentages are used (25, 50 and 75), based on which, the specialist measures the forced vital capacity of the lungs.

This instrumental diagnosis has a drawback, which is that pneumotachography is not suitable for detecting asthma caused by inhalation of an allergen.

This type of disease is called exogenous and occurs in patients who inhale seizure-inducing chemicals only while under certain conditions (such as at work).

Determination of allergic status

In order to accurately diagnose bronchial asthma, both injection and scarification tests are required. Often, the results obtained during a general blood test may be uninformative, therefore many doctors recommend that a biochemical analysis be done.

The study of blood serum is also necessary if the identification of the corresponding allergen is required. Under the influence of an allergic reaction in the body, the level of IgE (one of the types of immunoglobulin) changes, which will be reported by the test results.

To detect specific antibodies, there are special sets of allergens to which the sick person’s body reacts. Based on the results of testing, the doctor can accurately determine the root cause of asthmatic attacks.

If allergic asthma is suspected, skin tests are also done. Such a study is less informative than the determination of IgE in the blood, however, it is indispensable if the doctor is afraid of an anaphylactic reaction in the patient.

The patient should be aware that the test should not be performed in the presence of skin diseases such as eczema or atopic dermatitis. In addition, the test results will be unreliable if the sick person is taking antihistamines.

Features of the diagnosis of the disease in childhood

The occurrence of frequent coughing fits is typical for children, since it is at this age that the body is most susceptible to respiratory diseases. First of all, a doctor should prescribe a test that differentiates asthma of an allergic nature.

Noticing that the baby has begun to have coughing fits, parents should pay attention to whether the child coughs at night.

The development of common bronchitis is accompanied by the morning expectoration of sputum accumulated during the night, while asthmatic attacks are similar to whooping cough, and the child begins to cough up mucus during sleep. This information will be useful to a pediatrician who examines a small patient.

Thinking about how to recognize bronchial asthma in a child, parents should understand that the use of certain methods is necessary to make the correct diagnosis.

Prescribed drugs after this will prevent the progression of the disease. Confirming or excluding childhood asthma requires:

  • donate blood for analysis;
  • make an allergy test (according to the situation);
  • be examined using bronchodilators.

In almost one hundred percent of cases, the child’s disease is completely controllable if the correct diagnosis was immediately made.

With modern drugs and general strengthening of the body, it is possible to achieve reversibility of narrowing of the lumen in the bronchi and ensure long-term remission.


A person with chronic bronchial disease needs not only medicines, but also a change in lifestyle. For example, avoid contact with allergens.

By following medical prescriptions, the patient can reduce the occurrence of suffocating attacks to a minimum.

Knowing what asthma is and how to determine the cause of its occurrence, you can choose the right treatment and achieve long periods of remission and an improvement in the overall quality of life.