Österreichischer Selbsthilfeverein Lungenhochdruck

The left half of the heart pumps blood through our body while the right half of the heart pumps the blood into our lungs where it is loaded up with oxygen.

Normally, there is practically no pressure in the lungs so that the blood can circulate easily between the right half of the heart and the lungs.

However, if pressure does happen to increase here, it causes two serious problems:

•	The microscopically small lung vessels (which look like tiny branches) slowly start to close. They eventually grow together and then the blood can no longer reach all parts of the lung.
•	The right half of the heart therefore has to pump against a resistance (as if you are holding a hose-pipe squeezed shut behind the pump). This causes the heart to enlarge until eventually it results in a generally fatal right side heart attack.