U.S. Sen. John Fetterman's health is in the spotlight again after he felt "lightheaded" Wednesday night and was admitted to the hospital for observation.
It is not yet clear what caused the symptoms, though his office says initial tests found no evidence of one possible cause: a stroke.
The Pennsylvania politician suffered a stroke nine months ago, placing him at increased risk for having another one. Among other conditions that can cause lightheadedness are dehydration, infections, reactions to medication, and heart disease.
Here's what we know about Fetterman's health to date:
—Fetterman's atrial fibrillation
The politician's medical issues began in 2017, according to previous statements from his team.
That's when Fetterman developed swelling in his feet and saw an Allegheny County cardiologist, Ramesh Chandra. The physician diagnosed Fetterman with a common type of irregular heart rhythm called atrial fibrillation (A-fib).
In a letter provided by the politician's campaign, Chandra wrote that he prescribed medications, a healthy diet, and exercise, and recommended a follow-up visit within months.
Fetterman has said he undertook a weight-loss regimen afterward, shedding nearly 150 of his more than 400 pounds. But he did not take the medications and did not go to any doctor for 5 years, Chandra said in the letter.
—The stroke
On May 13, 2022, Fetterman's wife, Gisele, noticed that the left side of his mouth was drooping — a classic sign of a stroke — and insisted that he go to the hospital.
She was right. Fetterman's irregular heart rhythm caused a blood clot to form in his heart, and the clot migrated to his brain — the definition of a stroke.
The clot was promptly removed by physicians at Penn Medicine Lancaster General Hospital.
The politician's campaign did not provide details, but specialists not involved with his care said that means he underwent a thrombectomy. In that procedure, physicians insert a catheter into an artery in either the patient's groin or wrist, carefully threading it up all the way to the brain.
Such catheters are used to remove clots in one of two ways — either by pulling it out with a mesh tube called a stent retriever, or by aspirating the clot and removing it with gentle suction.
—The defibrillator
Four days later, physicians implanted a combination device called a pacemaker-defibrillator in Fetterman's chest.
As the name suggests, pacemakers help the heart maintain a steady pace.
A defibrillator, on the other hand, is used because the patient is thought to be at risk of a more serious problem: sudden cardiac arrest. Such devices are a miniature version of the paddles used by paramedics, delivering an electric shock to reboot the heart.
At first, Fetterman's campaign said the combination device was needed to treat his A-fib, and that he had no other heart issues.
The following month, in June, they said he also had a form of cardiomyopathy. There are several forms of that condition, but broadly speaking, it means the heart muscle is not pumping as well as it should.
—The rehab
Fetterman's speaking ability was impaired by his stroke, causing him to repeat words and sometimes use them in the wrong order.
This issue was not the result of any decline in cognitive skills, according to his campaign. It was caused by deficits in a communication skill called auditory processing.
Auditory processing refers to an array of brain functions that make hearing and speaking possible, including recognizing sounds as speech, mapping them against known words, and formulating a response.
Fetterman underwent months of rehabilitation exercises to improve his speaking ability, and he also learned to use coping strategies such as caption devices. Yet the lingering effects of his stroke were still apparent in his Oct. 25 debate with Republican challenger Mehmet Oz.
