Former President George H.W. Bush died Friday at age 94, less than eight months after his wife Barbara Bush's passing—an occurrence doctors say is common, Time reports.

Bush's health care legacy

Throughout his life, Bush was a strong advocate for individuals with disabilities. In 1953, decades before Bush would enter the White House, he and Barbara lost a child to leukemia. When he became president in 1989, Bush championed and signed into law the Americans with Disabilities Act (ADA), which prohibits discrimination against individuals with physical and intellectual disabilities.

Lex Frieden, a professor at the University of Texas Health Science Center at Houston and the former director of the National Council on Disability, said ADA is viewed as an antidiscrimination law equivalent to the Civil Rights Act. Frieden said ADA shifted how the public viewed disabilities.

After his presidency, Bush, who had been diagnosed with a type of Parkinson's disease, offered financial support to the Barbara Bush Children's Hospital and Mercy Hospital's Gary's House, which is a home for families whose relatives are receiving medical care at a hospital in the greater Portland area, WMUR reports. Bush also helped raise funds for various hospitals, including the emergency department at Biddeford's Southern Maine Health Care, which is named after his mother, Dorothy Walker Bush, according to WMUR.

Bush's passing

Bush reportedly fell ill in the months following Barbara Bush's death in April, People reports. According to People, Bush was admitted to Houston Methodist Hospital less than one day after Barbara's funeral to treat an infection that had spread to his blood. Bush later was hospitalized at Southern Maine Health Care to treat low blood pressure and fatigue.

His health appeared to continue to decline, People reports. Former Secretary of State James Baker said "things sort of went downhill" with Bush's health at the end of October. The cause of Bush's death was not immediately known Friday, People reports.

'Broken-heart syndrome'

Experts have said the emotional pain of losing a lifetime partner can take a toll on an individual's health, leading to a potentially fatal condition known as "broken-heart syndrome," or takotsubo cardiomyopathy, according to Time.

Martin Samuels, chair of neurology at Brigham and Women's Hospital, explained, "The brain has a system in it to deal with acute, serious, life-threatening stress. [With broken-heart syndrome], the stress is so great that the chemicals affect the heart such that it fails to contract normally," and the heart becomes misshaped, which reduces blood flow to the body. According to Samuels, broken-heart syndrome does not occur immediately. He explained that the condition is reversible, but it can compromise an individual's immune system and result in sudden death when cases are severe.

A study published in JAMA in 2014 found individuals who lost their spouses were more likely to have a heart attack or stroke in the 30 days following their spouses' death when compared with individuals who had not lost their spouses. Samuels said, "Losing a spouse is one of the most stressful circumstances that human beings have to face." He explained, "Any organ can fail, or all the organs can fail."

While Bush's death has not been directly attributed to broken heart syndrome, some said it was clear he was struggling with losing Barbara. David Valdez, Bush's former White House photographer, said, "A couple days after Mrs. Bush passed away, he went into the hospital, and we thought, you know, he's just dying of a broken heart. And I think these seven or eight months later, there's some of that there. They were so in love" (Ducharme, Time, 12/1; Jacobo, ABC News, 12/3; Withers, Vox, 12/2; Coveno, WMUR, 12/1; Zauzmer/Herbst, People, 12/1; AP/WPVI-TV, 12/2).