You hear it whenever someone gets sick or dies soon after losing a spouse: Was it because of a broken heart? Stress might not be to blame for former, but it does the body no favors, and one partner's health clearly affects the other's.
A sudden shock can trigger aor something like it called . Some studies also have found that people are more likely to die soon after losing a longtime spouse.
But often the timing is mere coincidence, and "broken heart" speculation just fuels a neat narrative when the problem is unsurprising in an older person with underlying health issues. Bush has suffered from a number of health conditions in recent years, including a form of Parkinson's disease and a serious.
In any case, the death of a loved one is a dangerous time for the surviving spouse, said Dr. Nieca Goldberg, a cardiologist at NYU Langone Medical Center and an American Heart Association spokeswoman.
"It's really important to have a lot of other support around you," she said. "When people are depressed after something like this happens, they may not be eating, they may ignore symptoms and want to be stoic. They're certainly stressing and may not be getting enough rest. All of these things can set the stage for life-threatening conditions."
Bush, who will turn 94 in June, has been hospitalized since Sunday with an infection that's spread to his blood. "Blood infections are very serious, particularly in the elderly," CBS News medical contributor Dr. David Agus told "CBS This Morning."
Stress weakens the immune system and can make infections harder to fend off, said several doctors, including Agus, who are not involved in his care.
"You couple that with sitting in a [funeral] ceremony where you're shaking lots of hands, greeting lots of people, hugging them, kissing them. The potential for spread of infection is real," Agus said.
It's possible the former president ignored early signs of infection during the flurry of preparations for Barbara Bush's funeral, said James Giordano, a Georgetown University neurologist and expert on stress's effects on the body.
"It could be something as simple as that; inattention led to an escalation of signs and symptoms," he said. "He's old, there's no good way to put it," so medical problems and risks are magnified by stress.
Stress has three stages, Giordano said: alarm, when the body releases "fight or flight" chemicals that can do damage; a resistance stage, like "calling out all the troops" to deal with the stress; and then fatigue or a letdown stage, when some of the body's defenses may crash from the strain.
Even if a partner's death is anticipated — as Barbara Bush's was after she decided to forgo more aggressive medical treatment and— "facing and going through the reality of the event" is stressful, he said.
Stress and a broken heart sometimes may get too much blame, though, when people are grieving.
Country music star Johnny Cash died four months after his wife, June Carter Cash, did in 2003. She was 73 and died of complications following heart valve surgery. He was 71 when he died of problems related to diabetes and had a neurological disease for years before that.
"Broken heart syndrome" was widely speculated when, in 2016. An autopsy later showed that Reynolds, 84, died of a blood vessel that ruptured and caused bleeding in her brain — a kind of stroke. She also had high blood pressure and other serious medical problems for several years before that.