West Palm Beach, Fla. ? Kristy Bryner worries her 80-year-old mom might slip and fall when she picks up the newspaper, or that she’ll get in an accident when she drives to the grocery store. What if she has a medical emergency and no one’s there to help? What if, like her father, her mother slips into a fog of dementia?

Those questions would be hard enough if Bryner’s aging parent lived across town in Portland, Ore., but she is in Kent, Ohio. The stress of caregiving seems magnified by each of the more than 2,000 miles that separate them.

“I feel like I’m being split in half between coasts,” said Bryner, 54. “I wish I knew what to do, but I don’t.”

As lifespans lengthen and the number of seniors rapidly grows, more Americans find themselves in Bryner’s precarious position, struggling to care for an ailing loved one from hundreds or thousands of miles away.

The National Institute on Aging estimates around 7 million Americans are long-distance caregivers. Aside from economic factors that often drive people far from their hometowns, shifting demographics in the country could exacerbate the issue: Over the next four decades, the share of people 65 and older is expected to rapidly expand while the number of people under 20 will roughly hold steady. That means there will be a far smaller share of people between 20 and 64, the age group that most often is faced with caregiving.

“You just want to be in two places at once,” said Kay Branch, who lives in Anchorage, Alaska, but helps coordinate care for her parents in Lakeland, Fla., about 3,800 miles away.

There are no easy answers.

Bryner first became a long-distance caregiver when, more than a decade ago, her father began suffering from dementia, which consumed him until he died in 2010. She used to be able to count on help from her brother, who lived close to their parents, but he died of cancer a few years back. Her mother doesn’t want to leave the house she’s lived in for so long.

So Bryner talks daily with her mother via Skype, a video telephone service. She’s lucky to have a job that’s flexible enough that she’s able to visit for a couple of weeks every few months. But she fears what may happen when her mother is not as healthy as she is now.

“Someone needs to check on her, someone needs to look out for her,” she said. “And the only someone is me, and I don’t live there.”

Many long-distance caregivers say they insist on daily phone calls or video chats to hear or see how their loved one is doing. Oftentimes, they find another relative or a paid caregiver they can trust who is closer and able to help with some tasks.

Yet there always is the unexpected: Medical emergencies, problems with insurance coverage, urgent financial issues. Problems become far tougher to resolve when you need to hop on a plane or make a daylong drive.

“There are lots of things that you have to do that become these real exercises in futility,” said Ed Rose, 49, who lives in Boston but, like his sister, travels frequently to Chicago to help care for his 106-year-old grandmother, Blanche Seelmann.

Rose has rushed to his grandmother’s side for hospitalizations, and made unexpected trips to solve bureaucratic issues like retrieving a document from a safe-deposit box in order to open a bank account.

But he said he has also managed to get most of the logistics down to a routine.

He uses Skype to speak with his grandmother every day and tries to be there whenever she has a doctor’s appointment. Aides handle many daily tasks and have access to a credit card for household expenses. They send him receipts so he can monitor spending. He has an apartment near his grandmother to make sure he’s comfortable on his frequent visits.