President Barack Obama received care at the Walter Reed military hospital after he started experiencing a sore throat on Saturday, the Daily News reported.
Captain Ronny Jackson, the president's doctor, said he should seek medical attention.
"Given that the president has free time in his schedule this afternoon, Dr. Jackson, the president's physician, recommended he go to Walter Reed for some diagnostic tests," White House spokesman Josh Earnest said in a statement. "According to Dr. Jackson, the quickly scheduled test is a matter of convenience for the president, not a matter of urgency."
After tests were done, the president was diagnosed with acid reflux. A fiber optic exam showed that his throat was swollen, and doctors performed a CT scan as well.
Acid reflux is when contents of the stomach flow back up into the esophagus from the stomach, causing heartburn and a sore throat, Reuters reported.
Jackson did not say how the president fell ill with the sickness. Risk factors include smoking, alcohol use and hiatal hernia, according to the U.S. National Library of Medicine.
During a physical in June, Obama was given a clean bill of health by Jackson, who also pointed out Obama's daily exercise and smoke-free lifestyle as main reasons he was free of ailments.
