Where there is air in healthy tissue in the lung tissue, water accumulates in certain diseases, which is squeezed out of the small blood vessels. The fluid displaces the air and can lead to severe respiratory distress. Read more about the development, typical symptoms and treatment of pulmonary edema.
How does a pulmonary edema develop?
The pulmonary edema can have different causes:
- Most commonly, it is due to cardiac insufficiency - the left heart muscle does not adequately pump blood into the large circulatory system, jamming it back into the pulmonary circulation. As a result, the pressure increases there and fluid is pressed from the smallest pulmonary vessels (capillaries) into the lung interstitium and the alveoli.
- Second most common cause with us is a kidney weakness. If this is pronounced, it leads to overhydration of the body, which in the blood relatively more water than large solid substances, especially proteins, is present. To compensate for the original ratio, water exits the blood vessels into surrounding tissue and accumulates in the legs, the abdomen (ascites) and in the lungs.
- But even lung diseases, pronounced allergic reactions or toxins can cause pulmonary edema. Reason in such cases is usually an increased permeability of the lung capillaries.
- The altitude sickness, drowning in salt water and massive hunger pains are rather rare triggers in our latitudes.
How is a pulmonary edema expressed?
The symptoms and findings vary in their severity depending on the stage of the disease. In the beginning, the fluid is only in the lung tissue itself, later the water enters the alveoli and even the small branches of the bronchi (bronchioles). The main symptoms are shortness of breath with rapid, shallow, strained breathing and coughing; those affected are very restless and often have chest pains. The shortness of breath can increase so much that the patient thinks he is suffocating.
Facial paleness and cyanosis (blue color of the lips, nails and mucous membranes) are also evident at this stage due to the lack of oxygen and frothy, sometimes slightly bloody sputum. Then, even without a stethoscope, typical "bubbling" breathing sounds (so-called rattling noises) can be heard. Without treatment, the disease results in a respiratory arrest with cardiovascular failure.