WASHINGTON (AP) — President Joe Biden has at least one thing in common with thousands of parents and grandparents this winter: He’s picked up a cold from his young grandson.

The president has had an unusually low, scratchy voice and an occasional cough all week, prompting questions from the press about his health on Friday. He assured reporters that he’s tested frequently for COVID-19 and is negative, and that has been dealing with a scratchy throat for a much less concerning reason.

“What I have is a one-and-a-half year old grandson who had a cold who likes to kiss his pop,” he said. “It’s just a cold.”

Biden spent the Thanksgiving weekend with his family in Nantucket, and on Monday, his youngest grandson Beau — named after Biden’s deceased son — was at the White House to help his grandmother welcome the White House Christmas tree.

Jill Biden picked a sprig off the tree and gave it to her grandson, along with a kiss.

Dr. Kevin O’Connor, who has been Biden’s primary care physician since 2009, released a note Monday affirming that Biden is “experiencing some increased nasal congestion this week.”

“This can be heard in his voice and he is feeling the colloquially well-known ‘frog in one’s throat,” O’Connor wrote.

He wrote that Biden was tested for 19 “common respiratory pathogens,” including the flu, COVID-19 and the strep virus, and all came back negative. The president is taking common over-the-counter medications to treat his symptoms.

Biden had his routine physical last month at Walter Reed National Military Medical Center, where his physician released a report declaring him a “healthy, vigorous, 78-year-old male, who is fit to successfully execute the duties of the Presidency.”

O’Connor investigated Biden for increased instances of “throat clearing” during public remarks and a stiffening of his gait. O’Connor reported that Biden’s coughing was the result of gastrointestinal reflux and that the stiffened gait was the result of a new diagnosis of “mild peripheral neuropathy,” spinal arthritis and compensation for a broken foot sustained a year ago.