There are a couple dozen other elements that are in there in trace amounts, but to a first approximation you're just a bag of carbon, oxygen, and hydrogen. Now, it turns out that the atmosphere is a bag of carbon, oxygen, and hydrogen as well, and it's not living.
Cigarette smoking is the most common irritant that causes emphysema. Pipe, cigar, and other types of tobacco smoking can also cause emphysema, especially if the smoke is inhaled. Fumes and Dust. Breathing in other fumes and dusts over a long period of time may also cause the disease.
What causes a pulmonary embolism? Blood clots can form for a variety of reasons. Pulmonary embolisms are most often caused by deep vein thrombosis, a condition in which blood clots form in veins deep in the body. The blood clots that most often cause pulmonary embolisms begin in the legs or pelvis.