A set of twins suffering identical strokes is rare. Add to that the fact that the twins are only 26 years old, and you've got what seems like a medical anomaly.

Arizona twins Kathryn and Kimberly Tucker suffered strokes 9 months apart, according to reports Wednesday. The two women are fraternal twins, which means their DNA is not identical, and have no history of stroke in their family.

"Honestly, it's rare for us to actually evaluate two sisters who've had strokes within months of each other," Dr. Joni Clark, a vascular neurologist at Barrow Neurological Institute in Phoenix, told ABC. "If they had a family history, it would not be a surprise. It's quite uncommon."

Here's what happened: Kathryn felt a sharp pain in the back of her head and on her right side shortly after going to bed. She then lost her vision and her body went numb. Kathryn's brother was in her apartment with her that night and was able to rush her to the hospital where doctors diagnosed her with a migraine.

Kathryn was sent home without being treated and said she slept for three days straight. "Then when I woke up my vision was horrible," she said. "Everything was distorted and one-dimensional. I could barely get around."

That's when Kathryn was taken to an urgent care facility where tests revealed that she had a stroke.

Just nine months later, after doing a 5K run, Kathryn's twin sister Kimberly said that her vision closed in, she felt a sharp pain in her left side, and she wasn't able to form complete thoughts. She immediately called 9-1-1, remembering what her sister had experienced.

"I instantly knew I had a stroke because I was suffering from many of the same symptoms as my sister," said Kimberly. "The EMTs told me that the chance of both me and my sister having a stroke this young was that of being struck by lightning twice. They thought I was suffering from dehydration or heat stroke."

Kimberly did suffer a stroke that day, which doctors discovered was attributable to her having an arrhythmia. Arrhythmias affect the rhythm of the heartbeat, which can be too fast, too slow, or simply irregular.

Her sister Kathryn was discovered to have a patent foramen ovale, or PFO. PFOs are holes in the heart that don't close the way they should after birth. The small hole could have contributed to Kathryn's stroke.

According to the Centers for Disease Control and Prevention, stroke is the leading cause of death in the United States. People who smoke cigarettes, drink excessive amounts of alcohol, and don't get enough exercise are all at higher risk for stroke. Obesity, heart disease, and high blood pressure can also be contributing factors. Typically, age is also an indicator of one's risk for stroke, with older people being more likely to have a stroke.

But over the last few years, research suggests that stroke patients are getting younger and younger. A study published in The Journal of the American Academy of Neurology found that strokes are increasing among adults aged 20 to 54, a trend likely linked to higher rates of obesity.

The Tucker twins, though young, did have some of the risk factors for stroke. They were both smokers and both had previously undiagnosed heart conditions. After occupational and speech therapy, the sisters report being in good health now, though they still have some visual impairments and are not allowed to drive.

"Don't think you are impervious to stroke," said Kimberly. "We think we are invincible until we are not. This taught us a huge lesson that we are not guaranteed great health and we need to take care of our bodies."