President Reagan at age 74 is in generally good health and has lower blood pressure than he had a year ago, but tests show he may be passing blood in his stool, according to results of his latest medical examination released Monday by the White House.

Reagan also had a small polyp, or tissue growth, 45 millimeters from his anal opening. The polyp proved to be benign, according to tests conducted last week by Dr. T. Burton Smith, the President's chief physician, and eight other doctors at the Naval Medical Command in Bethesda, Md.

"President Reagan continues to enjoy good health," said Navy Capt. Walter Karney, an internal medicine specialist who participated in the examination. "His overall physical and mental condition is excellent. I am especially impressed with the fact that his blood pressure is lower than a year ago--this is quite remarkable."