The Democratic candidate's health records were partially released after days of prevarication by her campaign and her collapse at New York's 9/11 memorial on Sunday.
But instead of ending speculation over her physical well-being, they contained a bombshell revelation that she had kept secret a condition so serious it led to surgery.
SCROLL DOWN TO READ HER DOCTOR'S VERDICT
Led away: Clinton aide Christine Falvo, a long-term volunteer and former State Department staffer, escorted the stricken Democratic candidate from the 9/11 memorial
Taking her pulse? Christine Falvo was seen holding Clinton's hand as the candidate's aides' concern mounted at her physical state and she was taken towards the Secret Service van at the 9/11 memorial on Sunday in New York
Supporting role: As Clinton collapsed getting into the Secret Service 'Scooby van', her aide Christine Falvo stopped her falling to the ground completely. It was hours before Clinton's campaign admitted just how ill she was
They revealed that in January she was suffering sinusitis and an ear infection for which she was given antibiotics and steroids.
The condition was diagnosed in the run up to the Iowa caucuses, the first electoral test for the candidate - but voters in the state were told nothing of what was wrong with her.
The condition is detailed in the letter from her physician, Dr Lisa Bardack, which then says that she continued to suffer ear pain.
Her ENT doctor, who has not been named, then examined her and she had a myringotomy tube placed in her ear to drain fluid. It appeared to alleviate her condition.
CLINTON'S VITAL STATISTICS The Clinton campaign released a letter from her doctor, Lisa Bardack, which set out key medical details about the Democratic candidate.
Medical conditions: Hypothyroidism and seasonal allergies
Blood pressure: 100/70
Cholesterol: 189 (LDL 103, HDL 56, tryglycerides 159)
Respiratory rate: 18
Height: not disclosed
Weight: not disclosed
Mental condition: 'excellent'
Medications: Prescribed Levaquin for bacterial pneumonia. Previously received anti-pneumonia vaccines Prevnar and Pneumovax, on undisclosed dates.Takes Coumadin, a blood thinner, also Armor thyroid and B12 'as needed'.
The letter does not spell out that this was a surgical procedure. It was followed in March by a brain scan, Dr Bardack discloses.
'This scan showed no abnormalities of the brain and mild chronic sinusitis,' Dr Bardack wrote.
'The symptoms resolved and she continued symptom-free for the next six months.'
The disclosure came five days after she was diagnosed with bacterial pneumonia - a full diagnosis which was only revealed on Wednesday, as well.
It came in a letter Wednesday evening that was posted to Clinton's campaign website, written on official letterhead for Dr Lisa Bardack, he personal physician.
It detailed that she first came to see Dr Bardack on Friday, September 2 - a week before the campaign had previously acknowledged.
At that time she was diagnosed with a 'low-grade fever, congestion and fatigue' and told to see her doctor when she returned from a campaign trip.
But a week later, she returned to Dr Bardack. A chest CT scan revealed signs of pneumonia,and she was given a 10-day course of antibiotics to treat the condition, that her daughter Chelsea says she didn't know about either until Sunday.
'The remainder of her complete physical exam was normal and she is in excellent mental condition,' Bardack's letter stated.
Clinton stayed off the campaign trail the two days following her initial visit with Bardack. She made her maiden voyage on her campaign plane on Monday to Ohio despite .
At the Labor Day event she suffered a prolonged coughing fit that she chalked up to an allergic reaction to her opponent. She told reporters the next day that she upped her antihistimines in response and would be better by the middle of the week.
On call: A man (pictured left, front, in light blue shirtt) arrived at Clinton's home Wednesday in a car with medical license plates; later, a deliveryman (right) brought Italian food
That was not the case, however, and Clinton made a second, secret visit to her doctor on Friday morning before a meeting with her national security advisers.
Bardack informed the presidential candidate she had pneumonia and needed to amend her campaign schedule. Clinton refused, and on Sunday she morning overheated after she was leaving a 9/11 event in New York City.
The letter from Bardack states:'On Friday, September 2nd, I evaluated Mrs. Clinton for a 24-hour history of a low grade fever, congestion and fatigue.
'On examination she was noted to have a temperature of 99.4; her vital signs were otherwise normal as was her physical exam.
'She was advised to rest, put on a short course of antibiotics, and continued on her allergy medications for an upper respiratory tract infection in the setting of her seasonal allergies.
'Over the next several days as she traveled, her congestion worsened and she developed a cough. She was advised to see me when she returned from her travels for further testing.'
Bardack writes that on Friday, Sept. 9, Clinton returned to her office.
'A non-contrast chest CT scan, including a CTA calcium score, was performed,' she says.
The letter is framed as an 'update' to the one she wrote when Clinton entered the race in April of 2015.
Additional health records released with the letter show that Clinton's cholesterol and blood pressure are within normal ranges.
She has had 'allergy flares' but those are 'typical' and have occurred throughout her lifetime.
Her immunizations are up-to-date, Bardack says, and she had a 'normal mammogram and breast ultrasound' this month.
CLINTON'S DOCTOR Diagnosis: Dr Lisa Bardack, the physician who wrote the letter
Lisa Bardack has been Hillary Clinton's 'long time' personal physician, caring for her since 2001
Dr Bardack, 52, works for CareMount Medical, a network of 400 physicians in New York State, where the Clinton have their home.
A New York University medical graduate, she is the group's chair of internal medicine and usually works at its Mount Kisco campus, close to Chappaqua.
The letter also notes that in January, during the run-up to the Iowa caucuses, Clinton received treatment for a sinus and ear infection that included placing a drainage tube in her left ear.
A CT scan of her brain and sinuses showed no abnormalities and mild chronic sinus inflammation.
'Mrs. Clinton had significant improvement in her symptoms,' the letter states.'Further follow-up evaluation with a CT scan of her brain and sinuses was done in March of 2016. This scan showed no abnormalities of the brain and mild chronic sinusitis.
'Her symptom's revolved and she continued symptom-free for the next six months.'
Clinton narrowly won the Iowa caucuses by less than one percent. She lost the next round, New Hampshire, to Bernie Sanders. Her performance in Nevada in February was lackluster, as well, though she did beat her opponent in the end.
It's unclear when Clinton had her out-patient surgery in March, the most important month of primary voting. More than half of 50 states cast their ballots in March alone.
That month Bernie Sanders began to surge, picking up unexpected wins against Clinton, who entered the race as the favorite. She didn't clinch the nomination until more than two months later as Californians took to the polls on the second to last day of voting.
Through the race Clinton has battled the perception that she's not been fully honest with the American people.
The disclosure of another secret medical treatment will only fuel questions in Democratic circles about the impact on Clinton's poll ratings for candor.
She had dismissed claims she had been unwell as conspiracy theories - but never told anyone she had been treated in January for an ear infection which involved the intervention with a drainage tube.
Clinton is largely viewed as untrustworthy by the voting public. She kept a private server in her home for four years as secretary of state that she housed her work-related emails against government guidance.
Her conduct was the subject of an FBI investigation that concluded this summer without criminal charges but had the bureau's director scolding her as 'extremely careless' with classified information.
It took the ex-cabinet official six months to apologize for the server that her boss, President Barack Obama, didn't know about.
A former adviser to President Obama, David Axelrod, blasted Clinton' this week for an 'unhealthy penchant for privacy that repeatedly creates unnecessary problems.'
Clinton's communications director admitted in response that the campaign 'could have done better' on Sunday while defending the Democratic candidate as more transparent that competitor Donald Trump.
WHAT IS A MYRINGOTOMY? HILLARY CLINTON'S SECRET EAR SURGERY EXPLAINED REASONS FOR A MYRINGOTOMY
Treating chronic ear infections that did not respond to antibioticsDraining ear fluid trapped for more than three monthsRestoring hearing loss from fluid build-upTo test fluid from the middle ear for bacteriaAccording to her doctor, Hillary Clinton developed an ear infection in January 2016.
Despite taking antibiotics, pain in her left ear persisted for weeks, getting worse and worse.
A doctor examined her and confirmed she had a build-up of fluid in her left ear.
That same month, she had a myringotomy to drain out the fluid.
HOW IS A MYRINGOTOMY PERFORMED?
The operation takes between 30 and 60 minutes.
First, the patient will be given an IV drip and general anesthetic.
Then the surgeon makes a small incision in the ear drum (using a scalpel or laser) to drain the fluid in the middle ear.
In many cases (like Clinton's), the surgeon places a tube through the incision to remain there after surgery.
That tube will drain fluid that collects after surgery, and allows air into the middle ear to help dry it out.
The ear drum wound heals itself so no stitches are required.
Patients are sent to the recovery room to be monitored.
They are strongly encouraged to eat or drink.
The tube inserted during surgery falls out on its own within several months.
Clinton's updated health history stated that she takes thyroid and allergy medicines and the blood thinner Coumadin, prescribed as a preventative after she suffered a blood clot resulting from a 2012 concussion.
The blood clot, which was in a vein in the space between the brain and the skull behind the right ear, led Clinton to spend a few days in New York-Presbyterian Hospital and take a month-long absence from the State Department for treatment.
Clinton has spent the past three days out of the public eye, recuperating at her suburban New York home. She'll return to the campaign trail Thursday, with a rally in North Carolina and a speech before a Hispanic group in Washington.
'I just talked to her she's feeling great and I think she'll be back out there tomorrow,' former President Bill Clinton said Wednesday, when he stepped in for his wife at a previous scheduled campaign event in Las Vegas.
And despite the massive pressure on her campaign to tell one true version of events, he described her illness as the 'flu'.
'It's a crazy time we live in, you know, when people think there's something unusual about getting the flu.'
After becoming dizzy on Sunday, Hillary Clinton retreated to daughter Chelsea's home, ditching her press corps for 90 minutes as Fox News reported that she had a 'medical episode.'
Coming out of Chelsea's apartment Clinton said she was fine, and returned to her home in Chappaqua.
The former first daughter said in an interview Wednesday with a North Carolina TV station that she had not seen the video of her mom getting woozy and struggling to stand - and that she didn't know about the pneumonia diagnosis until her mother arrived at her home.
'I just was so grateful that I got a chance to take of her for a little while. She's taken care of me my whole life, and she's just indefatigable,' Chelsea told Time Warner Cable News North Carolina's Tim Boyum.
'I don't think I've ever seen her so tired. And she was tired because she's had pneumonia,' Chelsea said, revealing that her mother kept her in the dark, too.
'So I think the fact that she didn't even tell me, and I talk to my mom every day, and am fiercely close to her, pretty much reveals that she thought it wasn't a big deal and she could just keep going.'
Chelsea said her mother viewed it as 'pesky pneumonia.'
'But even though she is a superwoman, she's still human, so I'm glad she finally listened to her doctor, took a few days off, and I know she's excited to get back on the campaign trail tomorrow.'
The campaign was more forthcoming about Tim Kaine, her running mate, than it was about Clinton, revealing his height and weight, which it did not publish for Clinton.
Vice presidential candidate Tim Kaine is in 'overall excellent health,' according to a letter the campaign also released Wednesday from his doctor, Brian Monahan, the attending physician of Congress.
It said Kaine is active in his work and physical fitness. He has never smoked and his alcohol use is 'modest.'
He's 5-foot-9 and weighed nearly 208 pounds during his last physical in February. An electrocardiogram of Kaine's heart was normal with the exception of 'left arterial enlargement.'
THE MEDICAL LETTER WITH SURGERY BOMBSHELL
BACTERIAL PNEUMONIA: EXPLAINED WHAT IS BACTERIAL PNEUMONIA?
Bacterial pneumonia is an infection of one or both of the lungs.
Unlike viral pneumonia, which is treated with rest and water, this infection requires a course of antibiotics.
The bacteria causes the lungs to become inflamed, filled with pus and fluid, making it hard for the body to process oxygen and carbon dioxide.
It means patients often struggle to breathe, become easily exhausted, and need more intense medical attention.
WHAT CAUSES BACTERIAL PNEUMONIA?
Most infections come from inhaling droplets of saliva or nasal mucus from sneezes, coughs or skin-to-skin contact.
The most common forms of bacteria that cause pneumonia are:
Streptococcus pneumoniae (lives in the nose and throat, can go on to enter the lung and bloodstream)Haemophilus influenzae (lives in respiratory tract)Klebsiella pneumonia (lives in the mouth, skin, digestive tract)Staphylococcus aureus (lives in the skin)WHO IS MOST AT-RISK?
InfantsAdults over 65People with weak immunityDrug abusersPeople with lung diseaseSmokersWHAT ARE BACTERIAL PNEUMONIA SYMPTOMS?
Coughing up thick yellow, green mucusCoughing up bloodSearing chest painSudden chillsFever above 102FLethargyMoist, clammy skinPalenessConfusion (common in adults over 60)Loss of appetiteHeadacheHOW IS IT TREATED?
Course of antibioticsOver-the-counter medications for cough or feverHOW TO AVOID BACTERIAL PNEUMONIA
You can avoid pneumonia by exercising, eating well, resting, and not smoking.
The CDC also advises that you wash your hands and use hand sanitizer regularly.
Young children should get the PCV13 vaccine, which comes in several doses for babies under one year old.