Biden is being treated by Dr. Timothy Gardner, medical director of the Center for Heart and Vascular Surgery at Christiana Care Health System, who said he likely will have a full recovery.
Biden has what the doctors "believe to be a mild stroke," according to Gardner. "[He is] "fully alert, in stable condition and has full motor and speech skills."
Hospital officials said Biden was communicating with his wife and parents, who were with him. He is being transferred today to Thomas Jefferson University Hospital in Philadelphia for "further observation and examination," according to the vice president's office.
Young adults under 45, like Biden, are not immune to stroke, the third leading cause of death in the United States, behind heart disease and cancer.
An estimated 10 to 15 percent of strokes -- most of them ischemic or due to blood clots, rather than hemorrhaging -- occur in those under 45, according to Dr. Aneesh Singhal, associate professor of neurology at Harvard Medical School, who practices at Massachusetts General Hospital in Boston.
Young men over the age of 30 are more prone to strokes than women, who are more vulnerable under 30. African Americans are also more likely to suffer a stroke at a young age.
Biden, 41, was elected as Delaware's attorney general in 2006. He recently served in Iraq for one year as a captain with the Delaware Army National Guard. He was considered a front-runner to fill his father's former U.S. Senate seat this November, but in January he announced he had decided against a run for higher office.
More 700,000 Americans, some of them young and seemingly healthy, have a stroke each year; women have about 55,000 more than men.
Because less is known about this disease among young people, the American Academy of Neurology has just received a grant to study stroke in that population, according to Singhal.
"The risk is still very low, but young men and women need to be aware," said Singhal. "Stroke is the leading cause of disability worldwide. It can happen in the young, and one of the real problems is they don't recognize the symptoms and it is often overlooked in the emergency department when they visit."
Just last year, a Wayne State University study revealed that young adults arriving in hospital emergency rooms after a stroke are often misdiagnosed.
Researchers found eight of 57 stroke patients were incorrectly diagnosed with conditions including vertigo, migraine, alcohol intoxication, seizure, an inner ear disorder or other conditions.
Stroke kills about 137,000 Americans a year, according to the Centers for Disease Control and Prevention. It is also the leading cause of disability.
About 6,400,000 stroke survivors are alive today; 2,500,000 are males and 3,900,000 are females, according to the 2010 American Stroke Month newsroom.
Studies show that about 795,000 people suffer a new or recurrent stroke each year. About 610,000 of these are first attacks and 185,000 are recurrent attacks. Women account for 60 percent of stroke deaths.
A stroke, sometimes called a brain attack, occurs when a clot blocks the blood supply to the brain (ischemic stroke) or when a blood vessel in the brain bursts (hemorrhagic stroke).