When friends heard I was in Michigan to help my elderly, macular-degenerated, moderately demented mother who had fractured her hip and been moved to a rehab facility, they told me not to forget to take care of myself. I’ve given other caregivers the identical advice. But now, after several weeks here, I wonder what it even means. How does it translate into reality?

I’m taking my calcium and eating my greens, but addressing my emotional needs would require taking time away from my mom’s bedside.

I picture myself meeting a friend for lunch, while back in rehab my mom lies shivering on the bathroom floor as her call button goes unanswered. Could I linger over coffee, in the name of self-care, knowing that were I at my mom’s bedside, her caregivers would be more . . . careful?

My mom and I have been at the rehab joint long enough for the overworked, underpaid care staff to have sorted itself into individual people and positions, some kind, some not. One aide sends a hunk of her $8 an hour home to Jamaica to pay for her own mother’s care. An Albanian aide says she hasn’t seen her mom in 11 years. They often work back-to-back 14-hour shifts.

I’m now familiar with some of the patients too, especially the screamers and fall risks and the troublemakers whose wheelchairs are parked at the nurses’ station so the staff can keep an eye on them. There’s the Russian woman whose hand flutters up as she apologizes to everyone who passes. I originally hoped she was saying “I’m soaring,” but it was just her accent. Next to her is the man who chews bloody sores on his arm and then cries out in pain.

I’ve gotten to know my mom’s nonspeaking roommate, or at least I’ve learned which TV shows she likes to have on at full volume while she sleeps. I hear that she was a nurse before her stroke.

The regular visitors, a coven of dutiful daughters who arrive daily bearing fuzzy slippers, favorite snacks, photos, have become my commiserators. I see them spooning food into their fathers or combing their mothers’ hair. When we find ourselves in the empty hall simultaneously seeking the elusive aide, we remind one another not to forget to take care of ourselves.

To that end, I don’t eat the leftovers off my mother’s tray. This doesn’t require much self-control, however, since even the cake looks nasty.

My mom has an hour of physical therapy daily, except when they are understaffed and sessions are canceled. This happens frequently, as if the administrators are caught off-guard by their rehab patients actually requiring rehab.

On the occasion when someone from therapy does appear, I burst out of the building as soon as they wheel my mom away, thrilled to have a precious, guilt-free hour. Giddy, I drive with the windows down, gulping the fresh breeze. I admire my fellow drivers and the beauty of the day, wondering what would be the most taking-care-of-myself option for my 60, now 52 minutes of freedom.

Loath to squander the moment, I pull into the closest parking lot.

The shelves of the CVS are wonderful! Colorful and bright! The staff cheerful and ambulatory! I buy a light-up Hello Kitty toothbrush that will remind me to brush a full minute each, top teeth and bottom. Now that’s taking care of myself.

I overstay a bit, and when I return, I see my mom’s call light on in the hall. How long has it been lighted? I hide in a doorway to spy, check my watch and begin to fume. When an aide finally appears, I creep closer and watch her grab my mom’s wheelchair from behind without a word.

If I’d been there, the aide would have asked my mom what she needed. She might even have called her “honey.”

When my mom sees me, she inflates. She’d been worried that I might not come today.

I remind her that I was with her all morning, until her PT. No matter. Now that I’m here, she’s happy, she feels safe and protected.

I drag myself back to her apartment at night, longing for a hot bath, but weighing it against equal time spent sleeping. Which one qualifies as taking care of oneself? I decide to allow myself a glass of wine. As I open the bottle, I imagine my mom as I left her, sleeping calm and cozy, dreaming of better times. But then the phone rings. It is the head nurse. My mother is not hurt, but she is confused and agitated. She’s trying to stand and walk. She’s anxious and uncooperative. “Perhaps it would help if you come back?”

I no longer find my fellow drivers delightful, nor do I enjoy the breeze. I seethe with resentment toward the world of people not sharing my misery. I’m sure that everyone but me is taking care of herself.

I find my mom at the nurses’ station parked beside the I’m Sorry Lady. Mom looks small and shaky. She doesn’t know where she is or why she is being punished. She does not know what she did wrong or why these strangers are mad at her. But the second she recognizes me, she relaxes.

I marvel at my power to bring peace. But as any superhero can attest, powers come at a price. If my presence can soothe and comfort her, then how can I withhold it? Who am I to take myself away? And that is when I understand that I can’t take care of both myself and her. It’s one or the other, one at a time.

Amy Goldman Koss is the author of “Side Effects” and other books for teens.