A 33-year-old who got light-headed at the gym tried to push through. He was having a stroke.

• A 33-year-old man felt light-headed in a workout class but it turned out he was having a stroke.
• Strokes occur when blood flow to the brain is blocked by a blood clot or ruptured blood vessel.

A 33-year-old man who was having a stroke when he felt light-headed in a workout class wants others to learn from his experience.

Alex McKeown, who is based in Chicago and works negotiating deals for large retail companies, told himself he could just push through when he felt light-headed, before sitting down at the gym.

Instructors called an ambulance, and by the time paramedics arrived he had lost control of his left arm and leg, and couldn't stand up by himself.

Doctors at Northwestern Medicine confirmed he was having a stroke and performed emergency surgery to remove a blood clot that was blocking blood flow into the right side of his brain.

McKeown's brain function returned to normal immediately after the surgery as it restored his blood flow.

Stroke is a leading cause of death in the US

More than 795,000 people every year have a stroke in the US, according to the CDC, and its a leading cause of death. Anyone can have a stroke but smokers, older people, and people with diabetes or high blood pressure are most at risk.

A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a blood clot or ruptures. This can cut off blood supply to parts of the brain, which means cells die.

The potential effects of a stroke vary depending on which part of the brain is affected, but they can include paralysis, memory loss, vision loss, and behavioral changes. It is possible to make a full recovery after a stroke if you receive treatment quickly.

According to the American Stroke Association, the warning signs of a stroke are face droopiness, arm weakness including difficulty raising the arms, and difficulty speaking or slurred speech. If you notice any of these symptoms you should call an ambulance immediately.

Other common symptoms are numbness, confusion, loss of balance, dizziness, a severe headache with no cause, and difficulty seeing.

Testing revealed a rare heart condition

Tests revealed McKeown had an aneurysm — which is a bulge in a blood vessel caused by a weakness in its wall — in his aorta, the main artery that carries blood away from your heart to the rest of your body.

"We did find an aortic aneurysm that would have otherwise been undetected in his lifetime, and undetected aneurysms continue to grow and ultimately cause a dissection or rupture which is catastrophic," one of his doctors, Dr. S. Christopher Malaisrie, said in a news release.

They also found that he had a rare heart disorder called a bicuspid aortic valve, which is associated with having an enlarged aorta. The 1% of the population affected by the condition are born with it.

McKeown will have open heart surgery later this summer to address this.

McKewon wants people to learn from his experience

McKewon is grateful to the fitness instructors for calling an ambulance and the team of doctors who treated him so quickly. "Without them, I likely would have gone home to sleep it off, and I probably wouldn't be talking or walking right now," he said.

"People think, this won't happen to me, but guess what? I thought that too," said McKeown.

He said that the biggest lesson he has learned from this experience is that if you think something could be wrong, you should seek medical attention straight away.