What Illness killed Muhammad Ali?

Friday, boxing legend Muhammad Ali will be laid to rest, one week after he died at age 74. Ali had been publicly battling Parkinson's disease for more than three decades, so it came as a surprise to many that his official cause of death, according to family spokesman Bob Gunnell, was "septic shock due to unspecified natural causes." "Sepsis is the body's overwhelming and life-threatening response to an infection, which can lead to tissue damage, organ failure and death," according to the CDC. The origin of Ali's infection has not been revealed, but the CDC stresses that an infection that starts anywhere in your body can lead to sepsis, even if it is only a minor one to begin with. The agency says there are more than 1 million documented cases of sepsis every year in the United States, including more than a quarter-million deaths.