However, after facing a chorus of questions about sudden weight gain, especially in his face, Flaherty revealed last year that he was suffering from a rare and painful skin condition known as bullous pemphigoid.
His reluctance to talk about the problem, which reportedly left him in severe discomfort, was evident when he disclosed his condition in an interview with the Globe and Mail. In international finance, continuity and stability in leadership are key, and people had been asking if he had cancer, if he was dying.
"And obviously, I am not," he said in the interview.
"I mean, I will die eventually, but not over a dermatological issue."
CBC reported a source close to the family said Flaherty died of a massive heart attack, but there was no official confirmation.
In the wake of Flaherty's sudden death Thursday, experts who treat bullous pemphigoid say the condition itself is unlikely to have directly triggered his death.
But side-effects of the high dose steroids he had taken to try to bring the condition under control could potentially have increased his risk of heart disease, suggested Dr. Julia Lehman, a dermatologist with the Mayo Clinic in Rochester, Minn.
"It wouldn't directly contribute to coronary artery disease, but it may worsen some of the risk factors for it, if a person had those," said Lehman, who was commenting in general terms as she did not treat Flaherty and would not have been able to speak about him if she had.
Bullous pemphigoid is an auto immune disease, a condition in which the immune system becomes over active and attacks the individual. There are a variety of auto immune conditions but in bullous pemphigoid the body attacks a layer of the skin between the outer strata, the epidermis, and the dermis below. That causes the painful blisters that are the hallmark of this condition.
Steroids are used to try to dial down the immune system, to bring it back towards the healthy balance where it protects against outside threats, but does not attack the individual.
But in some people, those drugs can increase the levels of bad cholesterol in the blood, trigger high blood pressure and-or increase the patient's blood sugar levels, Lehman said. That latter reaction can push a person into Type 2 diabetes.
"That happens to some patients," she acknowledged.
All three of those factors are known to increase the risk of heart disease. But it is not known if Flaherty experienced those side-effects.
Dr. Neil Korman, a dermatologist and professor at Case Western Reserve University in Cleveland, Ohio, has been treating bullous pemphigoid patients for decades.
He said Flaherty's death could have been completely unrelated to his skin condition.
"My opinion, from taking care of people with this disease for 30 years is that it's unlikely that this condition contributed," said Korman, who said he generally has between 50 and 100 bullous pemphigoid patients in his practice.
"They die with bullous pemphigoid, not from it. That's what happens. They die from something else, almost always.... If they died from bullous pemphigoid, it would not be from the disease, it would be side-effects of the medicine, it might be an infection from having raw skin open."
Infections at the sites of burst blisters are common with the condition, Lehman said.
While she concurred that Flaherty's death could well have been unrelated to his condition, she noted studies have shown a higher rate of death in people with the condition than those without it. One 2008 study suggested the mortality rate in bullous pemphigoid patients was double that of people who were unaffected by it.
"It is a condition that affects older individuals, so it makes it difficult to study which factors are contributing to mortality," Lehman said.
"But there have been some very well designed studies that have shown an increased mortality rate with bullous pemphigoid. But the condition itself is not thought to be the major contributor to death, but rather the complications such as infections or complications of the medications used to treat the condition."
Flaherty, who had been suffering from the bullous pemphigoid for over two years, was 64 at the time of his death.