Secretary of State Hillary Clinton remained hospitalized Tuesday for a blood clot in her head, but her doctors say she has no brain damage and is expected to recover completely.

Clinton, who fainted and suffered a concussion earlier this month, is being treated with blood thinners to help shrink the clot, which is in one of the veins between the brain and her skull.

"In the course of a routine follow-up MRI on Sunday, the scan revealed that a right transverse sinus venous thrombosis had formed,” Dr. Lisa Bardack of Mt. Kisco Medical Group in New York and Dr. Gigi El-Bayoumi of George Washington University said in a joint statement.

“This is a clot in the vein that is situated in the space between the brain and the skull behind the right ear.  It did not result in a stroke, or neurological damage. To help dissolve this clot, her medical team began treating the secretary with blood thinners. She will be released once the medication dose has been established.”

The statement helps answer questions about Clinton’s condition, outside experts said. “This is different than a lot of assumptions that people made, which is that it was a deep vein thrombosis in her leg,” said Dr. Alex Valadka, a spokesman for the American Association of Neurological Surgeons and a practicing neurologist in Austin, Texas.

The statement from Clinton’s doctors suggested she would recover fully.

“In all other aspects of her recovery, the Secretary is making excellent progress and we are confident she will make a full recovery. She is in good spirits, engaging with her doctors, her family, and her staff,” they said.

Valadka said such a clot can be very dangerous.

“This could potentially be very serious because so much blood goes through your brain,” Valadka told NBC news. “If you block one of the major draining pathways, you can get a stroke.”

Valadka said standard treatment would be to infuse a bloodthinner such as heparin right away, and to then put a patient onto blood thinner pills for a fews weeks or months.

“The interesting question is how is this related to her concussion, if at all?” Valadka asked.

Clinton, 65, is known for hitting the road hard and she’s logged close to a million miles in travel, having visited 112 countries while in office. She had planned to step down in 2013 and was widely considered a potential front-runner for the Democratic nomination for president, if she chose to run again in 2016.

The extensive travel and dehydration could predispose someone to such a blood clot, Valadka said.

“These dural venous sinus thromboses, they can happen spontaneously on their own without any trauma, without any blow to the head,” Valadka said. “Is it just a coincidence?”

But a blow to the back of the head could have damaged the vein, causing the clot, he added.

Dr. Jack Ansell of the New York University School of Medicine agreed.

“This condition is certainly not common but it’s not rare, either, and certain patients are prone to it,” Ansell said. “They include those who have head trauma, as she did, and people who have other underlying tendencies to have blood clots. It’s a serious problem but it is certainly one that is eminently treatable. I would expect her get better.”

Slideshow: A political life

Kevin Lamarque / Reuters

Hillary Clinton's life has taken her from first lady to senator to secretary of state.

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Courtesy of Lynsey Lee

Lynsey Lee, 19, was diagnosed two years ago with a blood clot in her left lung, months after she began taking the birth control pill Yaz.

Lynsey Lee hoped Yaz would relieve her severe menstrual cramping and pelvic pain, so she began taking the birth control pills when she was only 16. But, instead of getting better, she started experiencing extreme mood swings, nausea and even more pain.

“I got really, really sick,” says Lee, now 19, of White Bluff, Tenn. “I was just constantly throwing up, and it was getting hard to breathe sometimes.”

Then, she started having unbearable chest pains that sent her to the hospital what seemed like every few days. Doctors initially couldn’t figure out what was wrong. “They kept telling me that it was just my body getting used to the medicine,” she says. “Finally, [when I was 17] I just stopped taking it.”

Later that year, after numerous medical exams, doctors diagnosed a blood clot lodged in her left lung. During one emergency room visit, doctors asked Lee what would become a life-changing question for thousands of young women like her: “Have you ever taken Yaz?”

Now, she is among the more than 10,000 American women who have filed class action lawsuits or claims against the German pharmaceutical giant Bayer, which makes Yaz, a popular birth control pill. Thousands more claims are expected. In documents released Tuesday, the Food and Drug Administration raised questions about conflicting evidence about the risks of taking Yaz and other similar pills, including life-threatening blood clots, and said warning information should appear on labels for doctors and patients.

Thursday, the FDA's panel of outside experts voted 21-5 that current labeling on the medications isn't enough and should be updated with more information on the risks. But that news comes too late for Lee.

“I wish I had known before,” she says. “I never would have taken Yaz.”

A representative from Bayer said the company did not have an immediate response.

The side effects of taking the birth control pill that was touted as having fewer side effects than others have destroyed her life, Lee says.

She had been the captain of the high school dance team, but Lee said after she began developing symptoms, she had to sit on the sidelines because she couldn’t catch her breath. She ended up missing the second half of her senior year in high school, including her senior prom. But, she says, her biggest sacrifice was giving up a full dance team scholarship to Vanderbilt University -- all because of the blood clot that doctors can do little about.

Removing it is too dangerous, they say; Lee takes blood thinners and hopes the clot will dissolve and work its way through her system.

Today, Lee says, she lives with pain and fatigue and isn't strong enough to work. Instead of attending college classes to earn a business degree, Lee makes weekly visits to her doctor for monitoring.

She’s hired Oklahoma City attorney Noble McIntyre, a member of the attorney group The Injury Board, which advocates for patient safety. McIntyre represents 60 Yaz victims and partners with another firm representing 600 Yaz clients.

“She’s missed out on her youth, and she missed out on a scholarship that probably was worth $200,000,” McIntyre says. “We try to give our clients hope that somebody understands what they are going through. We’re trying to communicate with the defendant what these women, through no fault of their own, have experienced. She lost her prom. She lost her freedom, something so valuable to people, because she’s mostly confined to her home.”

Story: FDA panel: Add stronger warnings to birth control labels

Lee says she’s depressed because her compromised health keeps her from living a normal teenager’s life. “I cry a lot,” she says. "It just hurts so much."

She dreams of someday opening a pastry shop and bakes cakes now for her family when she’s up to it. Shehas helped coordinate fundraising efforts for the Ronald McDonald House and the St. Jude Children’s Research Hospital in Memphis. But she's still not sure what her future may hold.

“I don’t pray to get better because it’s in [God’s]  hands,” she says. “I pray for happiness.  I pray for others in this world that have it much worse than I do.”

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