He also met his doctor last week during a stopover to refuel in London on the way back from the US.
Buhari was accompanied to the Presidential Wing of the Nnamdi Azikiwe International Airport, Abuja, by some top government officials and presidential aides.
Addressing newsmen on Tuesday in Abuja, the PDP National Publicity Secretary, Kola Ologbondiyan, said the party was not against the President taking care of his health but that the truth should be told about his state of health.
President Buhari, before traveling to the United Kingdom for a four-day medical trip today, wrote to the Senate, seeking their confirmation of Mr Keyamo and the six others as chairman and members of the agency.
The four-day trip to the United Kingdom on medical vacation is to afford the Nigerian President the chance to see doctors to re-examine his health status.
Following Mr. Buhari visited Washington to meet with President Trump overdue every month, he surprised reporters by not only returning directly to Nigeria but instead making exactly what his media team predicted a "technological stop over" in London.
Buhari's medical trips overseas has sparked intense debate among Nigerians on social media.
Sismo de magnitud 6.9 sacude Hawái tras erupción del Kilauea
Las autoridades habilitaron dos albergues y evacuaron la zona residencial más próxima al volcán , conocida como Leilani Estates . El gobernador de la isla ha decretado el estado de emergencia ante el avance de la lava por el distrito de Puna.
"God sent me to become the next president of Nigeria".
When asked on the nature of Buhari's illness, Adesina declined giving details, adding that only the president can reveal that.
"Only last week, two days after his departure from the USA where he had gone for a state visit, Mr president's whereabouts was unknown".
"The President is going to receive some letters of credence from some new ambassadors posted to the country, that will last till about early afternoon".
The President is expected back in the country on Saturday, May 12th.
PDP noted that Nigeria under President Buhari "is awfully degenerating into a despotic state where citizens are no longer safe as long as they hold an opinion contrary to those in power, in spite of their constitutionally guaranteed freedom of expression".