As Clinton continues to recover, doctors look toward return home

In their statement, Lisa Bardack of the Mount Kisco Medical Group and Gigi El-Bayoumi of George Washington University said Clinton was making excellent progress and was in good spirits.

Clinton's complication "certainly isn't the most common thing to happen after a concussion" and is one of the few types of blood clots in the skull or head that are treated with blood thinners, said Larry Goldstein, a neurologist who is director of Duke University's stroke center. He is not involved in Clinton's care.

The area where Clinton's clot developed is "a drainage channel, the equivalent of a big vein inside the skull. It's how the blood gets back to the heart," Goldstein said.

Blood thinners usually are enough to treat the clot and it should have no long-term consequences if her doctors are saying she has suffered no neurological damage from it, Goldstein said.

Democrats are privately if not publicly speculating: How might her illness affect a decision about running for president in 2016?

After decades in politics, Clinton says she plans to spend the next year resting. She has long insisted she had no intention of mounting a second campaign for the White House four years from now, but the door is not entirely closed.

Beyond talk of future politics, Clinton's three-week absence from the State Department has raised eyebrows among some conservative commentators who questioned the seriousness of her ailment after she canceled planned Dec. 20 testimony before Congress on the deadly attack on the U.S. diplomatic mission in Benghazi, Libya.