After cancelling official duties, Queen Elizabeth II spent the night in hospital for tests.
On Wednesday afternoon, royal doctors sent the 95-year-old sovereign to see specialists in London.
Her Majesty was released, with Buckingham Palace stating that she was in “good spirits” following “preliminary investigations” during her hospital visit.
Her medical team was thought to have admitted her on Wednesday out of caution. And her first overnight stay in a hospital in eight years was for practical reasons.
Her Majesty, 95, was said to be back at her desk at Windsor Castle yesterday afternoon.
“Following medical advice to rest for a few days, the Queen attended hospital on Wednesday afternoon for some preliminary investigations, returning to Windsor Castle at lunchtime today Thursday and remains in good spirits,” the Palace said.
Queen Elizabeth was said to have spent the night at the unnamed London hospital because it was getting too late to take her on the 26-mile journey home.
She had not been hospitalized overnight since March 2013, when she was treated for a stomach bug at King Edward VII’s Hospital in Marylebone, central London.
It was thought to be her fifth major hospital visit in 40 years. Aides hope she will attend the COP26 climate change summit in Glasgow with world leaders on November 1.
Her Majesty cancelled a two-day trip to Northern Ireland on Wednesday, citing medical advice. Concerns were raised when she began using a walking stick during appearances at Westminster Abbey and the Welsh parliament earlier this month.
She was on her feet for more than an hour on Tuesday at a business summit at Windsor Castle. Since the death of Prince Philip, 99, in April, she has also decided to abstain from alcohol.