KEY WEST, Fla. (AP) — Endurance swimmer Diana Nyad has ended her fourth bid to swim from Cuba to Florida today after four days of storms, jellyfish stings and shark threats.

Nyad’s support team posted on her blog that the athlete made the call after being pulled from the water a day before her 63rd birthday.

Nyad left Havana on Saturday in her third attempt since last year to be the first person to swim the Florida Straits without a shark cage. She also failed once earlier to do so with a cage.

Nyad emerged from the water at 7:42 a.m. A team member, Vanessa Linsley, said earlier the swimmer was battered by a rough night and was unsure if she would be able to finish the 103-mile crossing.

“Instead of getting hit with one doozy they got hit with three,” Linsley said, “They got hit with the weather, they got hit with the jellyfish and they got hit with the sharks all at the same time.”

The overnight hours today marked the second straight night of storms encountered by the swimmer. On Monday evening, the swimmer’s crew was improvising ways to prevent hypothermia and to fend off further swelling of her lips and tongue. Though she was swimming in 85-degree waters, because that is lower than the body’s core temperature, it will reduce her body temperature over time. Her team said she had been shivering.

“We all know her mind can handle it,” Candace Hogan, a crew member traveling with Nyad, wrote on the swimmer’s blog. “But there will always be a point where a human body can’t go any further. What no one knows is where that line is drawn in Diana Nyad.”