Publicist Perri Cohen said in a statement Thursday that McCartney received treatment at a hospital in Tokyo. Cohen adds that McCartney is expected to make a complete recovery and will be taking time to rest.
McCartney cancelled his entire "Out There Japan Tour 2014" this week because of the illness.
The statement also says the 71-year-old "has been extremely moved by all the messages and well wishes he has received from fans all over the world."
The former Beatle will play a handful of shows in the United States starting June 14 in Lubbock, Texas.