Former President Daniel Moi on Friday went for a routine check-up at Nairobi Hospital.
He was later taken back to his home at Kabarnet Gardens.
Ugandan President Yoweri Museveni had earlier visited Moi during the last day of his official visit to the country.
"I also visited Mzee Moi and our Speaker, Rebecca Kadaga, who are in hospital. I wish them a speedy recovery," Museveni tweeted.
Moi, 94, has maintained a low profile since he left office in 2002.
Moi's last public appearance was on October 26, 2017, when he cast his vote at the Kabarak University polling station during the repeat presidential election.
His health has occasionally given him a scare, which saw him flown to Tel Aviv, Israel for a knee operation in March.
