George H.W. Bush Gives Photo Update From Hospital Bed

Former president George H.W. Bush is taking a “wonderful walk down memory lane” while in the hospital, he tweeted Friday.

Dressed in a hospital gown, the 41st president of the United States shared a photo of himself in a hospital bed with a copy of George & Barbara Bush: A Great American Love Story by Ellie LeBlond Sosa.

“Enjoying a great book and a wonderful walk down memory lane this morning. Yet another reminder of just how lucky I have been in life,” he wrote. “Very proud of the author and co-author too.”

The 93-year-old is back in the hospital in Biddeford, Maine, after experiencing low blood pressure and fatigue on Sunday, his spokesman Jim McGrath said in a statement on Twitter. While McGrath did not list Bush’s specific ailment, he said he would “likely remain [at Southern Maine Health Care] for a few days for observation,” and added that “the former president is awake and alert, and not in any discomfort.”

Bush’s return to the hospital came weeks after he was hospitalized in April for an infection, shortly after the funeral of his wife, former first lady Barbara Bush. He and Barbara were married for 73 years; she passed away peacefully at the age of 92 in April.

Bush’s long-time chief of staff, Jean Becker, admitted that the funeral had exhausted him.

“So many of you are asking, ‘How is 41?’ He, of course, is broken-hearted to lose his beloved Barbara, his wife of 73 years,” Becker wrote shortly after Barbara Bush’s passing. “He held her hand all day today and was at her side when [she] left this good earth.”

While President Bush has been battling various ailments for years, his symptoms reportedly matched those of takotsubo cardiomyopathy, or “broken heart syndrome,” a grief expert told PEOPLE.

“Broken heart syndrome is absolutely a real syndrome, a true medical condition,” said David Kessler, founder of Grief.com. “Grief is a reflection of the love. And the loss of a love so deep can actually be heartbreaking.”

“If two hearts have beaten in rhythm for 73 years, it’s not surprising that when Barbara leaves, that George considers following,” he explained. “They have a love story that not even a little death can stop.”

A day before his most recent hospitalization, the former president met with veterans at the American Legion Post 159 in Kennebunkport, Maine, according to a report by WCVB.

Bush, who frequently spends his time in southern Maine, spent Saturday morning at a monthly pancake breakfast with former military personnel and former National Security Advisor Brent Scowcroft.

Bush has reportedly spent every summer in Kennebunkport since he was a child, with the exception of the years he served in the U.S. Navy during World War II.