President Donald Trump will visit Walter Reed National Military Medical Center for the third time in just over a year as he struggles to hide a litany of health issues.

The president, who turns 80 in less than three weeks, has looked increasingly unhealthy during his second term, exhibiting frequent bruises, cankles, rashes, and questionable mental acuity that means freewheeling speeches and angry outbursts are more frequent than ever. He has also taken to falling asleep during high-level meetings, earning the nickname “Dozy Don.”

Tuesday’s visit to the medical center in Bethesda, Maryland—his fourth since retaking office—is under the microscope as a result, with a long list of physicians and other medical professionals sounding the alarm on Trump’s apparently waning powers.

Despite this, the White House regularly brags about the president’s vitality. This “lack of candor” has also raised suspicion.

“This White House just doesn’t seem to want to acknowledge any physical ailment, but older people develop medical issues, and the president is almost 80 years old,” leading cardiologist Jonathan Reiner told The Washington Post on Monday. “There just seems to be a lack of candor from the White House.”

In a separate interview with CNN, Reiner raised concerns about Trump appearing to fall asleep during Memorial Day commemorations on Monday, when the president was seen with his eyes closed for an extended time.

“The president has severe daytime somnolence. He falls asleep very often,” Reiner said.

“He’s fallen asleep in the Oval Office on multiple occasions with people talking to him in the Cabinet room, and I was concerned yesterday that he might have fallen asleep at Arlington National Cemetery during Memorial Day observances.

“Chronic insomnia is a severe illness. It can result in an increase in risk of dementia, decrease in cognitive effects in older people.”

In July, the White House was forced to confront the obvious after Trump paraded his bulbous ankles at several engagements. They were noticeable as he hosted dignitaries in the Oval Office, and as he sheepishly descended the stairs of Air Force One.