Dyspnea is the medical term for shortness of breath, which all of us have experienced at some point. Physiological—that is, non-pathological—causes of shortness of breath can include physical overexertion, high-intensity athletic performance, or being at high altitudes. Dyspnea is also a common symptom of various conditions, such as a simple respiratory tract infection, a respiratory disease (such as asthma), or lung and heart diseases. Details are explained in more detail below.
The body’s organs need oxygen to function. Oxygen enters the lungs via the airways. There, it passes into the bloodstream during a process known as gas exchange. The heart pumps the oxygen-rich blood throughout the body, supplying the organs. If they do not receive oxygen, they cannot perform their functions and may even die after a prolonged lack of oxygen. For this reason, a shortage of oxygen is immediately signaled to the brain, which triggers the sensation of shortness of breath.
Shortness of breath, another term for dyspnea, is a subjective sensation. The person affected thinks and feels that they can no longer get enough air. In response, their body increases their breathing rate.
Normally, a person takes about 15 to 20 deep breaths per minute. As the rate increases, these breaths become faster and therefore shallower, leading to shortness of breath.
By increasing the breathing rate, the body attempts to raise the oxygen level in the blood and thus compensate for the deficiency.
Oxygen enters the lungs through the airways and from there into the bloodstream. Oxygen deprivation leads to shortness of breath © Henrie | AdobeStock
Shortness of breath can be caused by a variety of conditions. In most cases, it is caused by a lung disease. Shortness of breath can occur as a symptom of the following lung diseases:
The heart is responsible for distributing oxygen throughout the blood. Therefore, heart diseases can also cause shortness of breath. Heart diseases that may be associated with shortness of breath include:
There are a wide variety of diseases affecting various organ systems that can cause shortness of breath. In addition to lung and heart problems, various laryngeal and tracheal disorders can also lead to shortness of breath. These include:
In addition, there are other diseases and situations that can cause shortness of breath. These include, for example, psychological causes such as a panic attack. A panic attack can lead to rapid breathing (hyperventilation). This means that the person breathes faster and faster, resulting in shallower breaths, which causes the CO₂ (carbon dioxide) concentration to rise and the O₂ (oxygen) concentration in the blood to drop. The body receives too little oxygen and cannot properly exhale carbon dioxide, causing shortness of breath.
But also
can lead to shortness of breath.
In addition to internal conditions, certain environmental factors can sometimes cause shortness of breath. For example, shortness of breath can occur at high altitudes during mountain climbing due to a lack of oxygen.
Furthermore, shortness of breath can be caused by foreign substances in the airways or by smoke inhalation. Extreme cold and heat can also lead to shortness of breath in sensitive individuals. In addition, pollen, dust, and grasses can cause dyspnea in patients with underlying allergic conditions.
Since shortness of breath can be triggered by various medical conditions, a medical evaluation is necessary. During this evaluation, the patient’s medical history is first reviewed. The doctor will ask about important lifestyle habits and circumstances, such as
- smoking habits
- pre-existing conditions, or
- medication use.
In addition, the circumstances surrounding the shortness of breath are examined in more detail. This includes, for example, the frequency of episodes as well as their duration, location, and time of occurrence.
Subsequently, various tests are recommended. During these, both the heart and lungs are auscultated with a stethoscope (also known as a “listening tube”) to check for any abnormal symptoms.
The physical examination includes a blood test and an electrocardiogram (ECG). An ECG records the heart’s electrical activity. This simple test, which has no side effects, can quickly and reliably determine whether acute heart disease is present.
A chest X-ray and a lung function test are also often performed. These provide information on whether there may be a dysfunction of the lungs or the airways.
The next steps depend on which conditions are suspected. Sometimes an allergy test or a biopsy can provide valuable information. In the case of a biopsy, a tissue sample is taken from the patient and then examined under a microscope.
Bronchoscopy or laryngoscopy can also aid in the diagnosis. In some cases, a computed tomography (CT) scan is necessary to identify the exact causes of shortness of breath.
Successful treatment of shortness of breath depends on the cause. Many mild forms of shortness of breath caused by inflammation or a viral infection of the airways resolve on their own with symptomatic treatment (rest, relaxation, bed rest, and warmth).
In severe cases of acute bronchitis or pneumonia, short-term antibiotic therapy may be advisable until the illness has fully resolved.
For other conditions, such as chronic obstructive pulmonary disease (COPD) or asthma, however, the patient must be treated with medication for the rest of their life.
In some cases, surgery or chemotherapy may also be necessary, such as in the case of a tracheal tumor.
