Hailey Bieber had a small stroke at age 25. It's unusual to have a stroke that young, but certain factors increase the risk.

• Hailey Bieber said she suffered a small stroke caused by a blood clot over the weekend. 
• Only 10% of strokes occur in people under 50, and the risk lessens the younger you are. 
• People of all ages should know their risks and the signs of stroke, like numbness on one side. 

Hailey Bieber is 25. She's said she eats a pescatarian diet, drinks plenty of water, and avoids sugar. She does Pilates and hot yoga on top of boxing and weight training, multiple outlets have reported. 

And yet, over the weekend, the model said she suffered a small stroke that landed her in the hospital. "Although this was one of the scariest moments I've ever been through, I'm home now and doing well," she shared on an Instagram story. 

Only about 10% of strokes occur in people younger than 50, and the risk goes down the younger you are, Dr. Donald M. Lloyd-Jones, president of the American Heart Association, told Insider.

But certain factors can raise your risk, and everyone should be aware of the signs so they can seek treatment as quickly as Bieber did. "Minutes matter in terms of saving brain tissue brain function," Lloyd-Jones said. 

There are two main kinds of strokes 

Strokes occur when there's a disruption of blood flow to the brain, typically either from a clot that's traveled to the brain or from spontaneous brain bleeding. Bieber said hers was caused by a "small clot." 

How a stroke is treated depends on how big it is, where it is, and what kind it is. A clot may be treated with a clot-busting medication, removed via surgery, or let pass on its own, as Bieber said hers did.

A stroke caused by brain bleeding could be stopped by reversing any blood thinning medications or by inserting a coil into the affected blood vessel, Lloyd-Jones, also chair of the Department of Preventive Medicine at Northwestern University's Feinberg School of Medicine, said.

How quickly patients get treatment affects the severity and length of any complications that follow, which can include UTIs, pneumonia, paralysis, speech and swallowing difficulties, memory loss, and even personality changes and a propensity for profanity. 

Birth control can increase the risk

Strokes are more common in women than men, with one in five suffering one in her lifetime, according to the American Heart Association. Women are also more likely to die from strokes. 

While some factors like race and a family history of strokes you can't control, others like not smoking and managing your blood pressure you can. 

Estrogen-containing hormonal birth control — especially among smokers — can also increase the risk. If you're concerned about your risk, talk to your provider about alternative contraceptive options,  Dr. Kelly Culwell, an OB/GYN in San Diego, previously told Insider.

"A lot of times," she said, "women just sort of take whatever they're given."

Young people may be more likely to miss the signs  

The AHA uses the acronym FAST to raise awareness of stroke symptoms. It stands for facial drooping, arm weakness, speech difficulty, and "time to call 911." 

While some symptoms like numbness may mimic other conditions like anxiety, Lloyd-Jones said a tell-tale sign of stroke is when the symptoms only occur on one side. 

Still, it can be easy to dismiss symptoms of stroke when you're otherwise young and healthy, as Bieber appears to be. Jayme Kelly, a 29-year-old nurse and CrossFit enthusiast, thought her numbness was due to sleeping on her limbs wrong.

But just a few hours later, she couldn't speak. At the hospital she learned she'd suffered a stroke related to a blood-clotting disorder that had gone undiagnosed. Now, 2 1/2 years later, Kelly remains out of work and in speech therapy, occupational therapy, music therapy, and psychotherapy.

She previously told Insider she wants people, and especially women, to put their health first. "Sometimes we need to focus on ourselves more and then we can focus on everyone else," she said. "And if I can have a stroke, so can all of you."