Former First Lady Barbara Bush spent New Year’s Day in the hospital and remains there today because of a respiratory illness.

Bush was admitted to Houston Methodist on Monday. Dr. Carmel Dyer of the UT Health Science Center told our TV partner Local 2 doctors were trying to play it safe because of her age.

“The immune function for her is not as strong as it is in younger patients,” Byer said.

Byer said pneumonia could lead to other health problems for patients like the former First Lady.

“If you’re older it can go to the brain and cause meningitis. It can also go to the heart,” Dyer explained, adding it is possible for it to cause a blood infection as well.

Family spokesman Jim McGrath says Mrs. Bush is doing as well as can be expected at this point.

“She’s in great spirits and getting great care. That’s all we can ask for at this point,” McGrath told KTRH. She’s a remarkable woman. I wouldn’t be surprised if she were to bounce back quickly.”

Mrs. Bush was hospitalized for a perforated ulcer in 2008. She also had heart surgery in 2009 and had a relapse of Graves disease in 2010. President Barrack Obama and Bill Clinton have both sent their wishes for a speedy recovery.

Barbara Bush is 88 years old.