Breathing and shortness of breath

The respiration rate, or the number of breaths you take per minute, affects how easily you get out of breath. An average healthy person gets out of breath if the volume of air inhaled per minute exceeds 70% of the person’s maximal ventilation.

Tobacco smoke reduces the oxygen saturation of haemoglobin and impairs the body’s oxygen uptake. Smoking also obstructs the bronchi, which, in turn, increases the oxygen consumption of the respiratory muscles and exercise-induced shortness of breath.

For more information and tips on how to quit smoking, visit our page on smoke-free living and the Stumppi.fi service of the Organisation for Respiratory Health in Finland. The free Stumppi helpline will help you on 0800 148 484.

Air pressure also contributes to shortness of breath. The higher above sea level you are, the lower the air pressure. The oxygen level of air is lower at high altitudes, such as in the mountains, causing the oxygen saturation of arterial blood to decrease. A reduction in the body’s oxygen uptake will rapidly lead you to feel tired and like you are running out of air.

On a plane, the oxygen content and saturation of arterial blood goes down to a level equivalent to moderate oxygen deficiency. This always happens, regardless of the fact that aircraft have been fitted with cabin pressurisation systems.

In healthy individuals, physical performance is usually limited by fatigue, muscle fatigue, and shortness of breath.

Exercise-induced shortness of breath occurs as a result of accelerated lung ventilation as the muscles require more oxygen-rich blood. If there is not enough oxygen in the blood, lactic acid will start to build up in the muscles. What this means is that the muscles take the additional energy they need by metabolising glucose.

The haemoglobin level of blood is of key importance to the oxygen transport capacity of blood and the body’s oxygen uptake. In men, the average haemoglobin level ranges between 134 and 167 grams per litre. In women, the average haemoglobin level ranges between 117 and 155 grams per litre.

A high haemoglobin level improves oxygen uptake. Individual differences have a significant impact on what the person’s general energy level is and how getting short of breath limits their physical performance.

Aerobic endurance decreases as you age. Regular exercise can help balance out the effects of age on oxygen uptake reduction to a certain degree.

For more information about forms of exercise suitable for people suffering from respiratory diseases, please visit Exercise for people with respiratory diseases.

Social interaction issues may be reflected in the way we breathe. Experiencing intense and recurrent feelings of fear and shame early in life may throw our breathing out of balance.

Emotions, attitudes, interpretations and impressions affect the functioning of the autonomic nervous system and the release of the stress hormone. This way, they also affect breathing, heart function, and blood pressure. Breathing difficulties increase emotional anxiety, which, in turn, makes breathing difficulties worse.

If you are experiencing breathing difficulties due to labour anxiety or other fears, you can seek support from healthcare professionals. Breathing difficulties can be alleviated by going over visualisation and relaxation techniques with a professional.

In addition to respiratory aspects, respiratory physiotherapy is used to assess and train functional ability and mobility. Respiratory physiotherapy is a complex process because breathing difficulties can be hard to identify. It is important to distinguish between a decrease in lung ventilation and hyperventilation, for example.

When breathing is not optimal for some reason other than a disease, this is called unbalanced breathing, or a functional respiratory disorder.

Unbalanced breathing is common. The symptoms are often dismissed as imaginary. On the other hand, sometimes a lot of tests are carried out to detect the cause. The symptoms of unbalanced breathing are not dangerous.

Symptoms of unbalanced breathing include

• absence of the normal post-exhalation pause
• holding your breath, which keeps the chest in the inhalation position
• higher respiratory rate at rest
• higher than average predominance of mouth breathing compared to nasal breathing
• activation of accessory respiratory muscles at rest
• frequent sighing and yawning
• abdominal muscle tension
• constantly needing to clear your throat
• air swallowing.

The human body tries to compensate for low oxygen levels by hyperventilating, that is, by accelerating pulmonary ventilation. Hyperventilation quickly leads to a feeling of getting out of breath.

Hyperventilating in the mountains can remove too much carbon dioxide from the body. This can lead to so-called mountain sickness. Symptoms of mountain sickness include headaches, dizziness, and increasing shortness of breath. The recommended first aid for mountain sickness is to quickly come back down closer to sea level.

People who are overweight may experience exercise-induced shortness of breath even during light exercise.

Excess weight interferes with breathing, the functioning of the diaphragm, and pulmonary gas exchange. Breathing difficulties are a common problem for people who are obese.

Abdominal obesity is particularly harmful. Men are classified as abdominally obese if their waist circumference is more than 100 centimetres, the recommended circumference being under 90 centimetres. Women are classified as abdominally obese if their waist circumference is more than 90 centimetres, the recommended circumference being under 80 centimetres.

Even with a normal BMI, a large waist circumference is harmful to respiratory health, regardless of age or gender. Asthma is also more common in people who are obese compared to people who are within the normal weight range.

For more information about exercise and nutrition, please visit our page Well-being and quality of life.