Shortness of breath

What is shortness of breath?

Shortness of breath, a symptom that can occur in many diseases, is the frightening feeling of not getting enough air. The complaint signals the difference between the ability to breathe and the need to breathe. If this requirement is not met, the body is in a kind of alarm state, which each person perceives as threatening to a different extent.

Shortness of breath is medically known as “dyspnea”. There are several forms. For example:

• Exertional dyspnea: shortness of breath during physical exertion
• Speech dyspnea: shortness of breath when speaking
• Resting dyspnea: shortness of breath at rest, without physical exertion
• Orthopnoea: shortness of breath that forces the patient to sit upright

We also distinguish between acute and chronic dyspnea. Acute dyspnea occurs suddenly, within minutes or hours, and is typical of an asthma attack or pulmonary embolism, for example, but can also occur in many other diseases. Chronic dyspnea develops slowly, over weeks or months, and is characterized by diseases such as chronic obstructive pulmonary disease, heart failure or pulmonary hypertension, but also occurs in various other diseases.

Frequency: Many people suffer from shortness of breath

Shortness of breath is a common symptom with different disease backgrounds. The most common causes of respiratory distress for which the emergency services are called and which occur in the emergency room or GP practice are

• Lung and respiratory tract inflammation
• Bronchial asthma
• Chronic obstructive pulmonary disease
• acute heart failure

Causes and risk factors: Heart, lung and systemic diseases

Respiratory distress is a complex symptom that can be triggered by an increased work of breathing, an excessively altered carbon dioxide content in the blood, blood and tissue hypoxia or other physiological changes. Shortness of breath can also appear as a reflex, for example in the case of severe pain, or it can be psychologically caused by great stress and other emotional strain.

The following diseases can be accompanied by shortness of breath:

• Bronchial asthma, chronic obstructive pulmonary disease, pulmonary fibrosis and emphysema
• Coronary heart disease and heart failure with pulmonary edema
• Pulmonary hypertension (high blood pressure in the pulmonary vessels)
• Pulmonary embolism
• Acute and chronic lung and respiratory tract inflammation
• Laryngeal and tracheal diseases
• Myocarditis and pericarditis, with or without pericardial effusion
• Pleural effusion (accumulation of fluid between the lungs and chest wall)
• Lung tumors, if they lead to complications
• Heart valve diseases
• Rib fracture, vertebral blockage, and aspiration of foreign bodies
• Smoke inhalation, sleep apnea and
• When staying > 2’500m above sea level altitude sickness
• Allergies
• Metabolic acidosis, i.e. metabolic acidosis in people with uncontrolled diabetes mellitus
• Neurological diseases
• Psychologically induced hyperventilation, for example due to anxiety or panic attacks
• Adverse drug reactions, for example due to levofloxacin, an antibiotic drug

Shortness of breath with COVID-19

Severe respiratory distress is also a symptom of COVID-19, which broke out worldwide in 2020 and triggered a pandemic. The disease is caused by the SARS-CoV-2 coronavirus, a highly contagious virus. The virus was first identified in China in 2019. It spreads primarily through droplet infection. After an incubation period of up to 14 days, the infection manifests itself with fever, a dry cough and other unspecific symptoms. Most people fall ill easily. As the disease progresses, however, some patients may develop severe shortness of breath due to life-threatening pneumonia . The latter require intensive medical treatment and ventilation.

Symptoms: The air stays away

The shortness of breath is recognizable by:

• Increased respiratory rate
• deeper breaths
• Use of the auxiliary respiratory muscles
• Cyanosis (bluish discoloration of the skin, mucous membranes, lips and fingernails) due to lack of oxygen
• Increased heart rate

The normal breathing rate depends on age. At rest it is normally:

• about 40 to 45 breaths per minute in newborns
• about 35 to 40 breaths per minute in infants
• about 20 to 30 breaths per minute in infants
• about 16 to 25 breaths per minute in a child
• about twelve to 18 breaths per minute in adults

Other symptoms often accompany the shortness of breath, such as

• Tightness in the chest
• Dizziness or nausea
• Fear or even panic

Assessment of the severity of respiratory distress

Shortness of breath can be harmless or life-threatening. It is important to correctly assess the severity of the complaint. We use the following classifications here:

Stages Classification according to NYHA (New York Heart Association) Classification of dyspnea

• NYHA I: (heart) disease without physical limitation. Everyday physical exertion does not cause excessive fatigue, arrhythmia, shortness of breath or angina pectoris.
• NYHA II: (heart) disease with slight limitation of physical performance. No complaints at rest. Everyday physical exertion causes exhaustion, arrhythmia, shortness of breath or angina pectoris.
• NYHA III: (Cardiac) disease with severe limitation of physical performance during usual activity. No complaints at rest. Low physical exertion causes exhaustion, arrhythmia, shortness of breath or angina pectoris.
• NYHA IV: (heart) disease with symptoms during all physical activities and at rest. Bedridden.

Borg Scale: Assessment method for classifying the severity of dyspnea on exertion

The Borg scale can be used to determine the individual feeling of exertion during physical exertion. The RPE value (Received Perception of Exertion) given during exercise is based on the assumption that the perception of exertion is related to the heart rate. The following formula is used for this purpose:

RPE = heart rate x 0.1

Since the resting heart rate is usually around 60 beats per minute, the Borg scale starts at 6, which corresponds to 60 beats per minute. The maximum heart rate in healthy people is usually around 200 beats per minute. That is why the Borg scale ends at 20.

Diagnosis: Complex and multi-layered, depending on the cause

A thorough medical history, i.e. questioning about accompanying symptoms and previous illnesses in combination with a physical examination, is crucial for the diagnosis of breathlessness. Subsequently, targeted further examinations are carried out. We will ask you the following questions:

• Do you suffer from lung, heart or other illnesses, such as allergies?
• Are you taking any medications?
• When exactly do you have breathing difficulties? After physical exertion or at rest? During the day or at night?
• Do you have any additional symptoms? Cough? Fever? Pain?
• Do you smoke? How much?

The physical examination includes listening to the heart and lungs. The following examinations are helpful in finding out the cause of breathlessness:

• Blood tests: They are primarily used to detect an infection of the respiratory tract and are only necessary in absolutely special cases of respiratory distress. Blood tests also show the condition of the kidneys and liver as well as the status of blood production, blood clotting, blood salts and blood sugar.
• X-ray of the lungs: This imaging procedure shows whether there are any visible changes in the lung parenchyma.
• Lung function tests, such as spirometry and whole-body plethysmography: We can assess lung function by measuring respiratory volume and airflow during breathing.
• Exercise tests: such as the 6-minute walk test or the bicycle ergometer test. These are extremely important for identifying the cause of breathlessness and for assessing its progression
• Blood gas analysis: This is the measurement of the oxygen and carbon dioxide content in oxygen-rich arterial blood.
• Bronchoscopy and biopsy: Bronchoscopy enables the mucous membranes in the trachea and bronchi to be visualized and tissue samples to be taken for fine tissue examination in the laboratory.
• Laryngoscopy: Laryngoscopy allows you to look into the throat to see if any changes are visible.
• Electrocardiogram: This is used to record the electrical activity of the heart and reveals whether there are any malfunctions.
• Echocardiography: The ultrasound examination of the heart is the most important non-invasive imaging examination in cardiology. It reveals functional and structural problems of the heart, such as the dimensions of each ventricle and the functionality of each heart valve.
• Allergy tests and inhalation provocation tests: These are mostly skin tests that reveal the allergen that triggers the allergy. In an inhalation provocation test, the suspected allergen is inhaled so that it can be determined whether it triggers the allergy.
• Computed tomography (CT) of the chest: This method allows an image of the airways and lung parenchyma to be obtained without overlapping. Many diagnoses are made on the basis of CT. (LINK UPDATES)
• Ventilation/perfusion scintigraphy: This is a nuclear medicine procedure that examines and images the ventilation and blood flow in the lungs.

Prevention, early detection, prognosis

Whether you can prevent shortness of breath depends on the cause. In the case of allergic bronchial asthma, for example, acute respiratory distress can be prevented if the person concerned avoids the allergen responsible and takes the medication correctly. People with respiratory, pulmonary and cardiac diseases can prevent worsening respiratory distress by not smoking or, if they are smokers, by quitting tobacco.

Course and prognosis

The course and prognosis of respiratory distress vary greatly and depend on the cause. Psychologically induced respiratory distress has a very good prognosis. The prognosis is less positive for chronic lung diseases and heart failure with pulmonary edema. Overall, the mortality rate for people admitted to hospital for respiratory distress is around ten percent.