Rumours and speculation have been swirling around Democratic presidential nominee Hillary Clinton‘s health ever since the 68-year-old stepped down as President Barack Obama‘s secretary of state in January 2014.

Initially reported as a concussion after a fall due to dehydration (which reports said was caused by a stomach virus), Clinton was eventually diagnosed with a blood clot near her brain (the medical term is cerebral venous sinus thrombosis, or CVST).*

As of late, her Republican opponent Donald Trump has brought up Clinton’s health issues, but many people have dismissed his remarks as a red herring, meant to detract from what some believe is a flailing, faltering campaign.

READ MORE: Dr. Drew questions if Donald Trump and his supporters are mentally ill

Trump said Clinton’s speeches are very short, and that she needs rest in the downtime between events — insinuating that her health is fragile.

Story continues below advertisement

“[Her speeches] don’t last long,” he said . “They’re like 10 minutes and let’s get out of here. Go back home and go to sleep. Three days later, she gets back up and does another one and goes back home and goes to sleep.”

On his daily KABC radio show, TV personality and medical doctor “Dr. Drew” Pinsky weighed in on Clinton’s potential health problems.

Dr. Drew says that he’s “gravely concerned” for Clinton, but not about her health. He believes she may not be receiving the right treatment for her condition. (You can hear the full audio below.)

READ MORE: Hillary Clinton faces wrongful death lawsuit from parents of soldiers killed in Benghazi

“She’s receiving 1950-level care by our evaluation,” said Pinsky. “She had two episodes of deep-vein thrombosis, she also has hypothyroidism. She’s being treated for that condition with something called ‘Armour Thyroid,’ which is very unconventional and something we used to use in the 1960s.”

He goes on to describe Clinton’s doctors’ medication choices as “weird,” saying “certainly a presidential candidate would get one of the newer anticoagulants.”

Story continues below advertisement

Pinsky also notes the rarity of her CVST (of which he’s only had one other case in his entire career), and that in order to have it something has to be wrong with her coagulation system.

“Oh, by the way: Armour Thyroid [is] associated rarely with hypercoagulability. So the very medicine doctors are using may be causing this problem, and they’re using an old-fashioned medicine to treat it — what is going on with her health care? It’s bizarre. Maybe they have reasons, but at a distance, it looks bizarre.”

READ MORE: Congress receives FBI notes from Hillary Clinton email investigation

Clinton released her full, recent medical records in July 2015, indicating that she is fit to run for president.

* CVST is a rare form of stroke, according to Johns Hopkins Medicine. It occurs when a blood clot forms in the brain’s venous sinuses. When the blood clot forms, blood can’t drain from the brain — ultimately, blood cells break and leak into the brain tissues causing a hemorrhage.

It’s incredibly rare, affecting about five in one million people each year, according to U.S. estimates. The symptoms include headache, blurred vision, fainting or loss of consciousness, loss of control over movement in parts of the body and seizures.

Story continues below advertisement

It can be potentially life-threatening, too. Complications from CVST include brain injury, impaired speech and developmental delays.

With files from Carmen Chai

Story continues below advertisement