From 1913 to the end of 1925, Alvarez practiced internal medicine in San Francisco and conducted research at the University of California, Berkeley.

His father was Luis F. Alvarez, who worked as a physician in California and Hawaii and developed a method for the better diagnosis of macular leprosy.

Alvarez was married to the former Harriet Skidmore Smythe[1] and the couple had four children: Gladys, Luis, Robert and Bernice.

Beginning after his retirement in 1951, Alvarez began writing a medical column which soon became syndicated throughout North America in hundreds of daily and weekly newspapers.

It may be caused when the muscles of the superior abdominal wall contract and push the contents of the abdomen inferiorly and anteriorly.