Albert Einstein, the famous physicist and Nobel laureate, died of an abdominal aortic aneurysm on April 18, 1955, at the age of 76. An abdominal aortic aneurysm is a bulge in the wall of the aorta, the largest artery in the body, which can rupture and cause life-threatening bleeding. Einstein had previously been diagnosed with the condition and had refused surgery, opting instead for medical management of his symptoms. When he experienced severe abdominal pain on April 15, 1955, he was taken to the hospital, where he was found to have a ruptured aneurysm. He died three days later, on April 18, 1955.