WASHINGTON (AP) _ President Bush's fainting _ blamed by the White House on a pretzel _ should have no long-term consequences for his health, doctors say. In fact, his good physical condition could have contributed to the incident.
Bush's physician, Dr. Richard Tubb, said the president began coughing while eating a pretzel on Sunday, stimulating a nerve that slowed his heart rate and caused him to lose consciousness briefly.
Often called the common faint, this type of event can affect medical students who see a lot of blood for the first time. It can also be caused by pain or fear or even straining to blow a trumpet.
Following his physical last August, Bush was pronounced in outstanding health. He exercises vigorously and regularly, and some experts say his type of faint may be more likely in people in good shape because their heart rates and blood pressure already are low.
A sudden drop in blood pressure can cause fainting by reducing blood flow to the brain.
The president was feeling better and back at work Monday, beginning a two-day trip to the Midwest and Louisiana, though he had a runny nose.
``My mother always said, 'When you're eating pretzels, chew before you swallow,''' Bush said. ``Always listen to your mother.''
For Bush, 55, the main consequences appear to be a scrape on his left cheek the size of a half dollar and a bruise on his lower lip from falling onto the floor from a couch.
Except for his two dogs, Barney and Spot, the president was alone, watching a football game, when the incident occurred.
Tubb was called to the White House on Sunday, and he also checked the president's vital signs on Monday. White House spokesman Ari Fleischer said everything checked out normal.
Fleischer said the president underwent an EKG test Sunday and his doctor saw no need for further tests. Bush had never before had a fainting spell, the spokesman said.
After his August physical, Bush's blood pressure was reported as 118/74, a reading Prof. James M. Hagberg of the University of Maryland called ``fabulous.''
Normal blood pressure can range from 110/75 in healthy young people to 130/90 in people who are 60 or so.
Following the fainting incident, Bush's blood pressure was 116/69, and just over an hour later it was 111/70.
The readings represent the relative pressure of the blood when the heart is pumping and when it is still. High blood pressure can lead to heart disease and stroke and often requires medical treatment.
Tubbs said that in Bush's case the cause appeared to be coughing that stimulated a long nerve that runs from the brain along the throat and down into the chest and intestines.
It's known as the vagus nerve and doctors call this type of fainting vasovagal syncope. Syncope (pronounced SIN-copee) is the medical term for fainting.
``We see a lot of it,'' said Dr. Lewis A. Lipsitz of Beth Israel Deaconess Medical Center and Harvard University, who has done research on fainting.
People may feel ill for a little while after fainting, Lipsitz said, but ``there are usually no consequences beyond that.''
Dr. David Skibbie of Inova Fairfax Hospital in suburban Virginia said fainting can be ``alarming, but if everything checks out it's fine and they can go home without any concerns about their future health.''
This type of fainting can be more common in healthy people because the nerve is more active, Lipsitz added.
The nerve could react to something in the upper airway or chest, he said, such as coughing after getting food caught in the throat.
A diagnosis of vasovagal syncope is usually made after physicians have ruled out more serious possibilities, said Lipsitz.
A vasovagal episode isn't the only possibility, Skibbie said. Somewhat less common is cough syncope, where a coughing episode _ similar to what Bush reportedly had _ can increase pressure in the chest enough to momentarily lower blood pressure. It, too, is benign.
Bush's parents both suffer from a thyroid disorder called Graves' disease which can cause a victim to become lightheaded
But the only previous medical problems reported by the president's doctors have been the removal of a few skin lesions caused by exposure to the sun.