The information should not be released to the public, but instead to trained medical professionals that can make informed statements about the impact of the information on the chances of death or loss of mental faculties while he is the President.  It shouldn't be released to the public because 1) the public won't understand the information, 2) If for example, the record shows he has Herpes, there is no reason for this to get out into the public realm as it has 0 effect on his long term health (and probably 0 effect on him at this age).

Then there was this in 1992

Four of Mr. Clinton's doctors in Little Rock, Ark., wrote letters made public by his campaign staff, and three of them spoke in interviews yesterday with Mr. Clinton's approval.

The letters from three doctors were more detailed than those that they released in June and the new ones included results of laboratory tests performed on Monday. The fourth letter was from a doctor who examined the Democratic Presidential candidate in September 1991 but who said she was not asked to write a letter in June.

Mr. Clinton, who is 46 years old, is seen frequently by doctors who give him allergy shots and treat his chronic laryngitis, but he has not had a full medical checkup in more than a year.

Dr. Susan M. Santa Cruz, a specialist in internal medicine, said the examination she performed on Mr. Clinton on Sept. 9, 1991, was his last and the only one she had performed on him. Dr. Santa Cruz said she wrote Mr. Clinton last month urging him to get a checkup. Repeated Requests for Details

"Obviously it is time for another physical, but we are just having a scheduling problem here," said Betsey Wright, a deputy campaign manager. "It's just one of those things that I don't think is going to happen until we get through this election, but we did do the blood tests because the doctors wanted current information to do these letters."

The release of more detailed medical information was in response to repeated requests from The New York Times and other news organizations. Mr. Clinton had previously not allowed his doctors to speak about his medical history, citing reasons of privacy.

I am in a hurry, but this suggests both candidates released health info in 1996.

See also

The reporters then had a conference call with McCain's doctors, who said McCain was in ''excellent health.'' The doctors said the melanoma in McCain's left temple, a potentially fatal form of skin cancer removed during surgery in 2000, had not recurred. The records also indicated McCain takes a statin for cholesterol, aspirin to prevent blood clots and medication to prevent kidney stones.

A week later, Barack Obama issued a six-paragraph, one-page letter signed by his physician of 21 years, Dr. David Scheiner. Scheiner's letter indicated Obama was in ``excellent health.''

Ronald Reagan, faced with concerns in 1980 that he would be the oldest person to be elected president at age 69, said in an interview with The New York Times in June 1980 that if he were elected to the presidency that November, he would have the White House physician periodically check his physical and mental state. He said he would resign if evidence demonstrated he was unfit. Reagan's mother, Nellie, had become senile a few years before she died at age 80.

Reagan's doctors at the time said he was in excellent health. Reagan had three major surgeries during his two terms in office, including having a bullet removed from his lung after he was shot on March 30, 1981. Besides that emergency procedure, he had a malignant polyp removed from his bowel in 1985 and a prostate resectioning in 1987. (He also had three cancerous skin lesions removed from his nose between 1985 and 1987.)

Reagan also occasionally dozed off in Cabinet meetings and had periods of forgetfulness. He left office in 1989, announced his Alzheimer's diagnosis in 1994 and died in 2004.

George H.W. Bush, who succeeded Reagan in 1989 at age 64, released medical records during his campaign and yearly during his presidency. His doctors said he had mild degenerative osteoarthritis in his hips, normal X-rays, EKG, urinalysis and blood work.