Former first lady Barbara Bush is receiving "comfort care" at her family's home in Houston after deciding she wanted no further medical treatment for unspecified health problems.
The 92-year-old has suffered from congestive heart failure and chronic obstructive pulmonary disease in recent years, and had surgery in 2009 for severe narrowing of her main heart valve. She also has been treated for decades for a thyroid condition called Graves' disease, and had surgery on a perforated ulcer in 2008.
A family spokesman did not elaborate on whether there were other health problems.
Here is what is known:
People who opt for comfort care receive treatment only for their symptoms, such as shortness of breath or pain, rather than trying to prolong life or cure the underlying health problem, said Tim Simpson, a certified hospice and palliative nurse for almost 28 years
For example, patients having trouble breathing might receive oxygen or steroids; or if they have fluid in their legs because of a bad heart, they might receive diuretics.
"With comfort measures, there are no unnecessary tests except those needed to relieve a patient's symptoms," said Simpson, chief nursing officer at Seasons Hospice in Illinois.
Hospice care has some technical differences. It's for patients who are not expected to live more than six months who sign a waiver officially saying they want only non-life-prolonging treatment of symptoms by a team of caregivers, and it may be covered by Medicare. Comfort care is more of a verbal understanding between doctor and patient, Simpson said.
Chronic obstructive pulmonary disease is a progressive lung disease that causes inflamed airways, which become smaller and impede a person's ability to get air out of their lungs, said Dr. Kyle Hogarth, a pulmonologist and associate professor in pulmonary and critical care at the University of Chicago Medicine.
Hogarth said because of the damage to the lungs, airways collapse easily, which is why patients have difficulty exhaling.
It's usually a combination of many things, including airway obstruction and emphysema, he said. People who are frequently diagnosed with bronchitis, especially in the winter, might have undiagnosed COPD, he said.
COPD usually is caused by smoking, though it can develop in nonsmokers, especially those exposed to second-hand smoke.
It also can indirectly affect the heart, which must work harder to pump blood through the lungs.