This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial infarction, myocardial rupture, cancer (most often Hodgkin lymphoma), uremia, pericarditis, or cardiac surgery, and rarely occurs during retrograde aortic dissection, or while the person is taking anticoagulant therapy. The effusion can occur rapidly (as in the case of trauma or myocardial rupture), or over a more gradual period of time (as in cancer). The fluid involved is often blood, but pus is also found in some circumstances. Surgery
One of the most common settings for cardiac tamponade is in the first 7 days after heart surgery. After heart surgery, chest tubes are placed to drain blood. These chest tubes, however, are prone to clot formation. When a chest tube becomes occluded or clogged, the blood that should be drained can accumulate around the heart, leading to tamponade. Pathophysiology
The pericardium, the double-walled sac surrounding the heart, consists of a fibrous pericardium layer on the outside and a double-layered serous pericardium on the inside. Between the two layers of the serous pericardium is the pericardial space, which is filled with lubricating serous fluid that prevents friction as the heart contracts. The outer layer of the heart is made of fibrous tissue which does not easily stretch, so once excess fluid begins to enter the pericardial space, pressure starts to increase. Consequently, the heart becomes compressed due to its inability to fully relax.If fluid continues to accumulate, each successive diastolic period leads to less blood entering the ventricles.
Sowda is a cutaneous condition, a localized type of onchocerciasis. : 440 
This is mostly seen in patients with the disease from Yemen, Saudi Arabia, East and West Africa

See also
Skin lesion


== References ==