Shortly after the nurse took her weight and her blood pressure—both of which were in the healthy range—Dr. Young entered the examination room.

“What’s up, doc?” he said and grinned. He was a short, balding, dark-skinned man with the compact build of a high school wrestler. He wore a blue dress shirt set off with a red bow tie, gray slacks, and black leather loafers. Like most modern physicians, he had ditched the clipboard and pen in favor of an iPad and stylus.

Sitting on the examination table, Monica offered a brief smile. Usually when she came in for check-ups, she and Dr. Young spent a few minutes catching up on their personal lives, but she didn’t have the energy to pretend that this was a routine wellness visit.

“Not feeling too hot these days,” she said. “I’ve recently picked up what seems like chronic fatigue. I’m also battling a case of severe arthritis, throughout all of my joints. The best way I can describe it is . . . I feel old.”

Dr. Young blinked, his jovial demeanor vanishing. He pushed up his wire-rim glasses, his copper-brown eyes intense.

“When did all of these symptoms begin?” he asked.

“Well, we had a death in the family recently—“

“I’m sorry, my condolences—“

“—so I’ve been feeling exhausted in general for the past week,” she said. “But the joint stiffness, the inflammation, that’s a new development. When I got up this morning, my knees ached so badly I could barely go down the stairs.”

“Have you had any unusual level of physical activity lately?” Dr. Young checked his iPad. “You run regularly, correct?”

“I haven’t been able to do any exercise. I’ve done nothing that would trigger this degree of inflammation. All I really do these days is sleep, to be frank.”

“How is the quality of your sleep?” he asked.

“It’s perfect. So deep, it’s as though if I’m drugged—and no, I’m not taking any medication for that, over-the-counter or otherwise. I’ve been taking naproxen for the inflammation, but nothing else. ”

“Does it help?” He tapped on his tablet, glanced at her.

“It’s temporarily effective at reducing maybe half of the pain.”

“So that’s a no.” He set aside his tablet on the table. “All right, let’s have a closer look at you.”

He asked her to remove her athletic shoes and socks. Kneeling, he examined her feet, gently clasped them in his cool hands.

“You’ve got a lot of swelling here,” he said.

“It hurts to walk. I was going to try soaking them this afternoon.”

Rising, he asked her to extend her arms. He examined her wrists

“Swelling here, too.” He picked up his tablet. “How’s your diet? Specifically sodium levels?”