There were too many dangers for Yossarian to keep track of. There was Hitler, Mussolini and Tojo, for example, and they were all out to kill him. There was Lieutenant Scheisskopf with his fanaticism for parades and there was the bloated colonel with his big fat mustache and his fanaticism for retribution, and they wanted to kill him, too. There was Appleby, Havermeyer, Black and Korn. There was Nurse Cramer and Nurse Duckett, who he was almost certain wanted him dead, and there was the Texan and the C.I.D. man, about whom he had no doubt. There were bartenders, bricklayers and bus conductors all over the world who wanted him dead, landlords and tenants, traitors and patriots, lynchers, leeches and lackeys, and they were all out to bump him off […].
There were lymph glands that might do him in. There were kidneys, nerve sheaths and corpuscles. There were tumors of the brain. There was Hodgkin's disease, leukemia, amyotrophic lateral sclerosis. There were fertile red meadows of epithelial tissue to catch and coddle a cancer cell. There were diseases of the skin, diseases of the heart, blood and arteries. There were diseases of the head, diseases of the neck, diseases of the chest, diseases of the intestines, diseases of the crotch. There even were diseases of the feet. There were billions of conscientious body cells oxidating away day and night like dumb animals at their complicated job of keeping him alive and healthy, and every one was a potential traitor and foe. (17.61-62)
Yossarian shows that he is paranoid about being killed not only by people, but also by his own body, which he eyes warily as a "potential traitor." Yossarian sees death everywhere around him.