Prince Philip,98, was not taken by ambulance and it is understood he will remain in hospital for a few days.
WATCH: The Queen and Prince Philip: 71 years of marriage in pictures
Earlier this year it was revealed the Queen was struggling to handle Prince Philip's continuous health concerns.
The Duke of Edinburgh retired from a life of royal duties in 2017 when he was 96-years-old, and since then the Queen's husbands health has been a serious cause for concern.
Questions surrounding Prince Philip's health were first raised by editor-in-chief of Majesty magazine Ingrid Seward, who discussed how Her Majesty has had to face the scandal of Prince Andrew's connection with sex offender Jeffrey Epstein alone, as the Royal Family faces it's most chaotic period in years.
The royal expert said: "This affects her deeply.
"For a start, her husband is 98 and probably not in the best of health, so, she hasn’t got him by her.
"This is her favourite son and she wants to protect him."
According to another source, Prince Philip suffered "a bit of a wobble" a few months ago.
WATCH: Queen Elizabeth and Prince Philip share rare tender moment on camera
The source told The Sun: "A few weeks ago Philip had a bit of a wobble and hasn’t felt so energetic.
"He has been living quietly at Sandringham, where he spends most of his time reading and pottering about.
"Until recently he has been very active — carriage riding, fishing at Balmoral and driving around royal estates — although he no longer drives on public roads following his crash in January."
The source continued: "His mind is as sharp as ever.
"However the sad reality is that the Queen is more isolated.
"They are both making an extraordinary personal sacrifice for the country."
