NEW YORK (CBSNewYork) – A terrifying, near-death medical crisis for a young actress from the hit show “Game of Thrones” has brought new attention to brain aneurysms.

Emilia Clarke suffered two ruptured brain aneurysms, either of which could have been fatal.

CBS2’s Dr. Max Gomez explains that aneurysms can happen at any age.

While they can occur at any age, Clarke was just 24 when she had her first. They become even more common with age.

Some aneurysms are congenital, some are caused by trauma or infections, and there is often a genetic predisposition to having aneurysms.

They are a weakening in the wall of an artery that can balloon out and rupture. They can be lethal if they burst and bleed into the brain.

Clarke had just finished shooting the first season of “Game of Thrones” back in 2011. Her childhood dreams of becoming an actress had just come true when her world nearly came to an end one day working out in a London gym.

“I’m doing the plank and I suddenly get this unbelievable pain and that felt very much like an elastic band around my brain. Excruciating,” the actress said.

An aneurysm in her brain had ruptured and started to bleed.

Stroke neurologist Dr. Carolyn Brockington explained that sudden, excruciating pain is usually the first sign of an aneurysm.

“It is the worst headache of your life. It’s all of a sudden. It feels like your head is exploding. Not your everyday headache,” Dr. Brockington said.

Emilia Clarke revealed her health crises in a first-person story in the New Yorker, where she describes surviving not one but two aneurysms.

“It can be devastating, causing a stroke. About 40 percent are fatal. Many times people are left with permanent disabilities,” Dr. Brockington added.

Emilia’s first aneurysm was treated with what’s called an endovascular technique. A catheter is threaded through an artery in the groin and into the brain where tiny metal coils are placed in the aneurysm to clot it off and keep it from bursting.

It was during this process that doctors found a second aneurysm in her brain which two years later had to be treated. It burst during the coiling procedure however, requiring open brain surgery to control the bleeding.

Despite long painful recoveries, Clarke appears to have survived her ordeals completely intact – and that’s unusual.

Many stroke patients who survive the ordeal do suffer some degree of brain damage. Surprisingly, aneurysms usually don’t cause any symptoms unless they happen to press on a brain structure like the optic nerves, causing vision problems.

Most aneurysms are found by coincidence when doctors are scanning the brain for an unrelated problem.