I notice it gradually, while exercising one morning. It’s a familiar routine, but that day bending over to touch the floor, leg lifted behind, I can’t hold the pose and my back gives way. The pain is insidious, then persistent. I go to work, hobbling throughout my day. Coworkers ask: What happened? Do you need something? Then they suggest: Try my chiropractor. Try downward dog. Here’s a hot pack. This is the only thing that helped my sciatica years ago. They’re all trying to be helpful but I can only wince. I can hardly walk. The pain is shocking, debilitating.

As a physician, I see people in pain every day. Pain from overexertion, pain from chronic illness, pain from medication side effects, pain from heartache. But to experience it myself, the slowing of body, the unexpected twitch of muscle with a movement, the limitations imposed by a body that isn’t working as it should, by a body that is a conduit for pain rather than a vessel for function: it’s humbling.

I don’t exercise for a week, then two. It’s hard to explain to others who only see me as able-bodied. They don’t realize. I shuffle as I cross the street; my husband and children walk casually ahead, so far ahead, on the crosswalk. I feel slow, I feel invalid. I get massage therapy, apply heat therapy, ingest ibuprofen religiously. The pain, initially searing in my back, flares unpredictably, shooting through my hip as I rise from sitting, as I twist to respond to a question, as I bend to pick up my baby from her crib.

A week into the flare, I just want to lie in bed, not get up, not go out. Though I am loathe to just lie there. I resent the creeping sluggishness. I want to defeat the lethargy and, simultaneously, be enveloped in it. I can suddenly see how people succumb: to numbing medications, to despair. Pain steals all functionality until the pain is all that’s left. And then it becomes your only companion. It is a cruel tease. One day or moment might feel a bit better, hope rises. Then, cruelly, it dissipates as the pain roars back.

One day I wake and can sit up without wincing, can walk with only a slightly antalgic gait. Everyone asks: How are you feeling? I feel tentative. I feel better. I feel anxious that it might come back, might return to level me again. I’ve learned now, it’s taught me. Pain is a presence, but also a thief.