According to a spokesperson, he was admitted to the ICU at Houston Methodist Hospital to address an acute respiratory problem stemming from pneumonia.
Doctors performed a procedure to protect and clear his airway that required sedation. President Bush is stable and resting comfortably in the ICU, where he will remain for observation.
Additionally, Mrs. Bush was admitted to the Houston Methodist Hospital Wednesday morning as a precaution after experiencing fatigue and coughing.
PHOTOS: George H.W. Bush and Barbara Bush through the years
George Bush is shown with wife Barbara in 1945. (AP Photo)none
In this 1964 file photo, George H.W. Bush sits on couch with his wife Barbara and their children. George W. Bush sits at right behind his mother. Behind couch are Neil and Jebnone
George H. W. Bush with his wife, Barbara, and their children Pauline and George W. on horse in the yard of their Midlands, Texas ranch.none
(Original Caption) George W. Bush with his father George Bush and mother Barbara in Rye (New York). (Photo by Robert Daemmrich Photography Inc/Sygma via Getty Images)none
(Original Caption) George Bush, Neil, George W. Bush, Barbara, Jeb and Marvin. (Photo by Robert Daemmrich Photography Inc/Sygma via Getty Images)none
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George Herbert Walker Bush poses with his wife Barbara during his campaign for Congress in the 1960's.none
United States Ambassador to the United Nations (and future US President) George H.W. Bush sits with his wife, Barbara Bush, and the couple's daughter, Dorothy in DC in 1971none
U.S. Vice President George H. W. Bush, right, and his wife Barbara Bush pose in front of the Taj Mahal on Saturday, May 13, 1984, Agra, India. (AP Photo/Sondeep Shankar)none
President Reagan shares a laugh with first lady Nancy Reagan and the Bushes at night on Wednesday, August 22, 1984 in Dallas after the Republican National Conventionnone
Senate candidate George Bush shows a victory sign as he and his wife Barbara stand in front of a vote machine November 3, 1964 in Houston just before casting their ballot.none
George Bush is sworn in as new director of the CIA by Supreme Court Associate Justice Potter Stewart, left, as Mrs Barbara Bush and President Gerald Ford, at right, look onnone
President Gerald Ford and first lady Betty Ford visit with George Bush, chief of the United States Liaison office, and his wife Barbara at the U.S. Liaison in Peking, China, Dec. 4none
President-elect Ronald Reagan and his wife Nancy wave from the balcony at the Kennedy Center on Jan. 18, 1981, where they attended a concert George H.W. Bush and his wife Barbara.none
U.S. Vice-President George H.W. Bush and wife Barbara Bush as they toured the Guilin area, Oct. 13, 1985 in China. (AP Photo/Neal Ulevich)none
With King Hussein of Jordan, at the helm, VP George H. W. Bush, and their wives, Barbara Bush, second from left, and Queen Noor, cruise while staying at the king's guest housenone
VP George Bush and wife, Barbara, wave to supporters that turned out in Houston to hear him announce he was a candidate for the Republican nomination for president on Oct. 12, 1987none
George Bush and his wife Barbara cast their votes in Houston for the Texas senate primary race, June 6, 1964.none
Former President Ronald Reagan, his wife Nancy Reagan, new first lady Barbara Bush and her husband President George Bush, right, walk down the Capitol steps after the inaugurationnone
Republican presidential candidate George H.W. Bush, with wife Barbara looking on, speaks to a gathering at a GOP Victory '88 reception held at the Ontario Hilton Hotel June 6, 1988none
VP George Bush and his wife Barbara Bush are shown during a fundraiser in Washington where he picked up the endorsement of President Reagan in his bid to become the next presidentnone
President-elect George H.W. Bush, right, and his wife Barbara, wave to the crowd at a victory celebration rally, Tuesday, Nov. 8, 1988, Houston, Tex. (AP Photo/J. Scott Applewhite)none
President-elect George Bush and his wife Barbara are shown during a morning beachfront news conference in Gulf Stream, Fla., Nov. 14, 1988.none
President-elect George Bush and his wife Barbara are shown during a morning beachfront news conference in Gulf Stream, Fla., Nov. 14, 1988.none
President George H.W. Bush, left, and first lady Barbara Bush smile as well-wishers wave U.S. flags upon their arrival on the south lawn of the White House in DC July 18, 1989.none
VP George H.W. Bush, right, and his Barbara Bush talk to reporters after a press conference outside their home, Sept. 3, 1988, Washington, D.C. Bush said he was standingnone
Pres. George H. W. Bush, left, and First Lady Barbara Bush wave to U.S Marines at the desert encampment during a Thanksgiving visit, Thursday, Nov. 22, 1990, Saudi Arabia.none
U.S. President George H. W. Bush and his wife Barbara smile as the audience applauds after the president spoke July 12, 1989 at Karl Marx University of Economics in Budapest.none
President-elect George Bush and wife Barbara during a beach front news conference, Monday, Nov. 14, 1988 in Gulf Stream, Fla.none
Vice President George H. W. Bush, center, poses with his family outside St. Anns Church, Sunday, Aug. 8, 1988, Kennebunkport, Me.none
President-elect George Bush and his wife Barbara are shown during a morning beachfront news conference in Gulf Stream, Fla., Nov. 14, 1988.none
Pres. George H. W. Bush and First Lady Barbara Bush return to the White House from Camp David and are met by the family dogs, Sunday, Sept. 16, 1990, Washington, D.C.none
Vice President George H.W. Bush, right, and his Barbara Bush, holding the family dog, talk to reporters after a press conference outside their home, Sept. 3, 1988, Washington, D.C.none
Pres. George H. W. Bush and Barbara Bush, center, smile and wave a final goodbye to Soviet Pres. Mikhail Gorbachev and his wife at the completion of the four-day superpower summitnone
Pres. George H. W. Bush and First Lady Barbara Bush, and their guests, West German Chancellor Halmt Kohl and French President Francois Mitterrand at the Economic Summit, Houstonnone
President George H.W. Bush and Mrs. Barbara Bush accompany Queen Elizabeth II and her husband Prince Philip across the South Lawn of the White House.none
Barbara Bush watches as President George H. Bush reels in a fish aboard their boat fidelity on Wednesday morning, August 7, 1991 just off shore from their vacation homenone
U.S. President George Bush and first lady Barbara Bush stand at attention together with Japan's Emperor Akihito and Empress Michiko during a ceremony in Tokyo, Jan. 8, 1992.none
Entertainer Bob Hope applauds as President George H. W. Bush kisses his wife Barbara during a pre-election rally at the Astro Arena in Houston in this Nov. 2, 1992 file photo.none
First lady Barbara Bush smiles standing by donkey as President George H.W. Bush looks on at the Houston Livestock Show and Rodeo, Feb. 28, 1992 in Houston.none
The Bushes made an impromptu stop at the Houston Rodeo to shake hands with people attending the event. (AP Photo/Doug Mills)none
President George Bush awards Sam Walton the Medal of Freedom as first lady Barbara Bush looks on during ceremonies at Wal-Mart headquarters in Bentonville, Ark., March 17, 1992.none
First lady Barbara Bush wags a finger at a donkey as President George H.W. Bush looks on at the Houston Livestock Show and Rodeo, Feb. 28, 1992 in Houston.none
Pres. Bush George H. W. Bush and First Lady Barbara Bush wave goodbye as Japanese Prime Minister Toshiki Kaifu choppers away from the Presidents home in Mainenone
President George H.W. Bush and Mrs. Barbara Bush walk arm in arm towards Marine one on the lawn of the White House, Washington on Sunday, Oct. 11, 1992.none
Pres. George H. W. Bush and First Lady Barbara Bush, and their guests, West German Chancellor Halmt Kohl and French President Francois Mitterrand at the Economic Summit, Houstonnone
Pres. George H. W. Bush, left, and First Lady Barbara Bush wave as they arrive at Newark International Airport on their way to New York, Saturday, Sept. 29, 1990, Newark, N.J.none
Former President George H.W. Bush, first lady Laura Bush, President Bush, and former first lady Barbara Bush wave to reportersnone
In this March 29, 2015, former President George H.W. Bush and his wife Barbara Bush, left, speak before the NCAA basketball tournament in Houston.none