He is expected to spend around a week in London resting and meeting doctors, according to members of the Pakistan Muslim League-Nawaz (PML).
"My father reverently kisses my grandma's hand as she surrounds him with prayers for his health before seeing him off," Maryam Nawaz Sharif tweeted as Sharif left for the Lahore Airport earlier in the day.
Interior Minister Nisar Ali Khan stated that the Prime Minister has been facing heart problems for the past many years which have exacerbated in the past two to three months.
Khantold Pakistani media that, "He (Sharif) had taken time from doctors earlier as well, but he could not attend his appointments. The PM, on my advice, had agreed to go on a separate visit for medical treatment."
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Sharif has arrived in the UK amid a raging controversy back home surrounding his family over the 'Panama Papers' issue.
The Prime Minister and his family have dismissed allegations of money laundering and denied any wrongdoing but the opposition is demanding an independent probe.
Nisarsaid earlier today that Sharif had announced the formation of judicial commission to investigate allegations of offshore companies.