The Queen, who grew frailer and suffered mobility problems in her twilight years, was in robust health for most of her life and seldom took time off during her lengthy reign.
When she was waylaid by the odd cold or flu, she chose not to make a fuss.
Like her eldest son, the Prince of Wales, and the Queen Mother, she was a firm believer in homeopathy, often turning to herbal remedies to cure any ailments.
Many of us can often take steps to eat better food or take more exercise
The Queen in her Commonwealth Day message in 2006
She saw the importance of keeping fit, offering such health tips in her 2006 Commonwealth Day message at the age of 79.
“Many of us can often take steps to eat better food or take more exercise,” she advised.
Even in her later years, the Queen travelled thousands of miles across the world to far-flung destinations such as Australia and Singapore, keeping to a tightly packed, busy schedule.
Her official foreign trips became shorter, and eventually the Queen called time on her overseas visits, with the younger generation of royals taking on her duties abroad.
Sometimes royal tasks took their toll.
In 2004 the Queen, at the age of 78, nodded off while listening to a speech on a trip to Germany.
She closed her eyes for about 10 seconds during a university lecture on the use of magnets in healthcare.
As the Queen prepared to turn 80 in 2006, the Duke of York spoke about how she was approaching her role in her later years.
“She is incredibly fit. But we remind staff that she’s not just the monarch but our mother,” Andrew said.
“There’s no need to do six engagements in a day. You can achieve the same amount of connection and consistency at a different pace.”
The Queen’s illnesses were few and far between over the years.
She fell ill shortly after giving birth to Charles.
As a new mother in January 1949, she caught measles and had to be separated from her baby son.
The first time the Queen was admitted to hospital was in July 1982 when she had a wisdom tooth extracted at King Edward VII’s Hospital in central London.
In March 1993, she was forced to cancel several engagements because she had flu.
Prince Edward stood in for her at a reception given by the Commonwealth secretary-general and a service at Westminster Abbey.
However, in the same month, she refused to cancel a visit to a handbag factory, despite having had three stitches in her left hand after being bitten by one of her corgis.
The Queen’s approach to injury and illness was perfectly illustrated in 1994.
She broke her left wrist when her horse tripped during a ride on the Sandringham estate in Norfolk.
The break was not diagnosed until almost 24 hours later, when her arm was X-rayed and set in plaster at a hospital.
It was the first time she had fallen in many years and the Queen had simply brushed herself down, remounted her horse and trotted on back to Sandringham.
In January 2003, the Queen was at the exclusive King Edward VII’s Hospital for keyhole surgery on her injured right knee.
She had torn a cartilage when she jarred the knee while walking on rough ground during a private visit to Newmarket, Suffolk.
A 45-minute operation to remove the cartilage was a success and the Queen used a walking stick during convalescence when her official engagements were scaled down.
Later that year, in December, she returned to hospital for a similar operation on her left knee.
At the same time, surgeons removed minor – non-cancerous – growths from her face in a double procedure lasting an hour and a quarter.
In June 2005, she unusually cancelled three engagements after catching a bad cold and suffering from a sore throat.
She was also said to have suffered from sinus trouble, which she reportedly treated with homeopathic pills containing grains of deadly nightshade.
In October 2006, the Queen pulled out of a visit to the new Arsenal football ground after straining a muscle in her back, which happened during her summer break at Balmoral.
Doctors advised her to reduce her workload and said they were reviewing her progress on a daily basis.
She cancelled an appearance at a Buckingham Palace investiture, with her daughter, the Princess Royal, stepping in.
But she was there for the annual State Opening of Parliament, which required the wearing of a heavy crown and sitting in the same position for some time.
As one aide put it at the time: “She’ll be there. She’s such a trouper.”
In February 2009, it emerged that the Queen had cancelled a state visit scheduled to take place in the spring.
The Palace insisted this was due to “other commitments”, not her age nor the health of the Duke of Edinburgh, who was suffering from a bad back.
The Queen had last cancelled a tour during the 2003 Iraq War and, before that, following the September 11 attacks.
In June 2009, she cancelled an appearance at an investiture ceremony after catching a cold and in April 2011 she pulled out of a service for the Royal Victorian Order at Windsor Castle after suffering a nosebleed.
In October 2011, she missed a visit to the British Museum in London after coming down with a cold ahead of a visit to Australia, with aides saying it was a precaution as she needed to be fit for the long-haul trip.
In October 2012, she missed a church service in Crathie on Deeside during her summer stay at Balmoral because of a sore back and later that month an investiture at Windsor for the same reason.
Her first hospital stay in 10 years came in 2013 when she was 86, after she suffered symptoms of gastroenteritis and missed an engagement in Swansea on March 2 when she was due to present St David’s Day leeks to the 3rd Battalion The Royal Welsh.
On March 3, she was admitted to King Edward VII’s Hospital to be assessed.
A week of engagements, including a two-day trip to Rome, was cancelled.
The Queen spent one night in hospital and left thanking staff and smiling before being driven to Buckingham Palace to rest.
It was thought her public appearances were back on track until Buckingham Palace announced on the morning of the Commonwealth Day Observance service on March 11 that she regrettably could no longer attend “as she continues to recover following her recent illness”.
It was the first Commonwealth Day Observance service she had missed in 20 years, the last occasion being when she had flu in 1993.
The Queen, who placed great importance on her role as head of the Commonwealth, did however attend the Commonwealth Reception at Marlborough House on the evening of March 11 to sign the new Commonwealth Charter.
Buckingham Palace insisted it was just the “tail end” of the symptoms and that her condition had not worsened.
But the next day she cancelled her engagements for the rest of the week, with the Duke of York saying later that it was sensible not to risk her going out, but that she was not ill.
She carried out her first public engagement in more than a week on March 20 2013, when she and the Duke of Edinburgh joined the Duchess of Cambridge at Baker Street Underground station in London to mark the 150th anniversary of the Tube.
On November 12 2013, the Duke of Cambridge stepped in to represent the Queen at an investiture ceremony after she suffered some “mild discomfort” with her ankle following a busy weekend of engagements including the Festival of Remembrance and the service of remembrance at the Cenotaph.
In 2014, the Prince of Wales stood in for the Queen for part of the Order of the Bath service to avoid her having to make an extra journey up and down some steep steps in full regalia.
She turned 90 in 2016 and, the same year, used the lift rather than stairs to enter Parliament for the State Opening, avoiding the 26 steps of the royal staircase at the Sovereign’s Entrance.
Buckingham Palace said the “modest adjustment” to arrangements were made for “the Queen’s comfort”.
The decision was put down to the Queen suffering from knee pain.
Both the Queen and the Duke of Edinburgh fell ill with heavy colds before Christmas in 2016, forcing them to delay their trip to Sandringham by a day.
The Queen was not well enough to attend the Christmas Day service at St Mary Magdalene Church and also missed the New Year’s Day one.
She later described it as a “particularly grisly mixture of cold and flu”.
The Queen kept up her passion for horse riding, even in later years.
In April 2017, just after her 91st birthday, she was seen out on her fell pony in Windsor Great Park.
In November 2017, the Queen asked the Prince of Wales to lead the nation in honouring the country’s war dead on Remembrance Sunday at the Cenotaph.
It was the first time that the Queen, as head of state, had watched the ceremony from a nearby balcony, and was seen as a sign of the royal family in transition and an acknowledgment of her age.
In May 2018, the Queen had successful surgery to remove a cataract from one of her eyes and wore sunglasses at a number of events.
At the end of June 2018, she pulled out of a service at St Paul’s Cathedral because she was feeling “under the weather”.
She also missed the christening of her great-grandson, Prince Louis, on July 9 2018, but not because of illness.
It was mutually agreed by the Queen and the Duke and Duchess of Cambridge that she would not attend the celebration, which fell at the beginning of a busy week of engagements including the centenary of the RAF and a visit by then US president Donald Trump.
In January 2020, the Queen missed her annual visit to the Sandringham Women’s Institute due to a slight cold.
During the coronavirus pandemic, the Queen retreated to Windsor Castle for her safety, where she was joined by Philip in lockdown.
The couple were vulnerable to Covid-19 because of their advanced age, but were protected by “HMS Bubble” – their reduced household of about 20 staff.
In January 2021, the 94-year-old Queen and the 99-year-old duke received their coronavirus vaccinations, with Buckingham Palace taking the rare step of confirming what would usually have been a private medical matter, as the national rollout of the injections gathered pace.
After Philip’s death in April 2021, the monarch quickly returned to official engagements – at an age when most people would have retired more than 30 years earlier.
In October 2021, the sovereign used a walking stick at a Westminster Abbey service – the first time she had done so at a major event.
A week later, after a busy autumn programme, she was ordered to rest by royal doctors and advised to cancel a trip to Northern Ireland.
The Queen was secretly admitted to hospital for “preliminary investigations” and had her first overnight stay in hospital for eight years on October 20 2021.
The next day she was back at her desk at Windsor, carrying out light duties.
But concern for her health mounted when she pulled out of more major engagements including the Cop26 climate change summit and the Festival of Remembrance, with the Palace saying she had been advised to continue to rest and to not carry out any official visits.
She was intent on attending the Remembrance Sunday service at the Cenotaph, but missed this due to a sprained back.
For more than three months, she carried out only light duties including virtual and face-to-face audiences in the confines of Windsor Castle.
In February 2022, she celebrated her Platinum Jubilee, meeting charity workers at Sandringham House and cutting a Jubilee cake in what was her largest in-person public engagement since October.
Many of her duties were carried out by video calls, and she remarked during a in-person audience: “Well, as you can see, I can’t move.”
But there were major fears for her health when she finally caught Covid, testing positive on February 20 2022.
The triple-vaccinated Queen suffered from mild cold-like symptoms, but said the virus left her “very tired and exhausted”.
She carried on with light duties while self-isolating at Windsor but cancelled some virtual audiences.
She pulled out of the Commonwealth Day service at Westminster Abbey in March, a significant date in the royal calendar given the importance to her of the Family of Nations, and did not attend the Maundy Thursday service.
But she rallied to honour the Duke of Edinburgh at a memorial service at the end of the month, walking slowly and carefully with the aid of a stick, and holding on to the Duke of York’s elbow for support.
In May, she missed the State Opening of Parliament for the first time in nearly 60 years due to “episodic mobility problems”, with the Prince of Wales taking her place and reading the Queen’s Speech for the first time.
However, the Queen did attend the Windsor Horse Show the same month and was the guest of honour at the equestrian extravaganza A Gallop Through History near Windsor, the first major event of the Jubilee festivities.
She also made a surprise appearance to officially open the Elizabeth line at London’s Paddington station, looking bright and cheery, but with her visit limited to just 10 minutes.
The Queen also turned up at the Chelsea Flower Show, and was driven around the floral extravaganza in her new hi-tech golf buggy for her comfort.
Her historic Platinum Jubilee celebrations proved a challenge in June 2022 due to her ongoing mobility problems, but she managed to make three balcony appearances and a beacon lighting.
She pulled out of attending the Jubilee service of thanksgiving in St Paul’s Cathedral due to the physical demands involved, and also missed the Epsom Derby.
The Duchess of Cambridge said the Queen, who appeared in public for just over 27 minutes during the four-day weekend, found the first day “very tiring”.
The Queen’s final balcony appearance rounded off the end of the festivities, and in a written message she appeared to acknowledge the health and age constraints she was facing when she pledged to continue to serve as monarch “to the best of my ability supported by my family”.
In September 2022, outgoing prime minister Boris Johnson and incoming PM Liz Truss travelled to Balmoral for audiences, rather than making the Queen return to London – the first time in her reign the Queen had appointed a leader in her Scottish home.
The next day, she postponed a virtual Privy Council after doctors ordered her to rest after her “full day”.
Fears dramatically escalated for the Queen’s health on Thursday September 8 when the Palace announced the Queen was under medical supervision at Balmoral.
The royal family including all of the monarch’s four children and the Duke of Cambridge and the Duke of Sussex made the urgent dash to be by her bedside.