Marie Sullivan says that she knew something “wasn’t quite right” during a doctor visit five years ago.

“I thought I might be anemic, but the results of my annual physical were fine,” she recalled. “All my numbers were in the normal range. The blood work turned up nothing. I said to my doctor, ‘Are you sure? What’s wrong with me?’ ”

Her doctor blamed her age, but Sullivan, 55 at the time, wasn’t buying it. “I’m not that old,” she said. “I know you slow down as you age, but I’m physically exhausted all the time. And I know I’m not the only person who feels this way.”

Lassitude. Weariness. Fatigue. Whichever term you prefer, recurring tiredness seems to be the new normal for a growing number of people, regardless of their age or background. Typical causes include illnesses such as anemia, depression, hypothyroidism, diabetes and heart disease.

But increasingly, medical professionals are looking at a new source of the problem: the increasing overuse of technology and its implications on our mental well-being.

Yes, Facebook, Twitter and Instagram can wear you out, said Patricia Bratt, a therapist and psychoanalyst with offices in New York City and Livingston, N.J.

“Social media can run the gamut from being fabulously uplifting to being totally depressing and exhausting,” said Bratt, who is also the director of trauma and resilience studies at the Livingston-based Academy of Clinical and Applied Psychoanalysis. “And this applies to all ages.”

Bratt works with young adults who check their social media constantly and at all hours of the day and night. They all complain about being tired.

“It impacts their sense of themselves and their identities and makes them anxious,” she said. “Social media has created a new sense of impulsivity and urgency, it can make them feel overwhelmed by what is happening in the world, and all of these factors can be fatiguing and can affect how they sleep.”

In July, a survey conducted by the National Safety Council found that 43 percent of respondents said they do not get enough sleep to think clearly at work, make informed decisions and be productive.

Age not an excuse

Dr. Maria Vila, a physician at Atlantic Health System’s Chambers Center for Well Being in Morristown, N.J., said fatigue is one of the most common complaints among her patients. And, no, she doesn’t think “You’re getting older” is a particularly helpful diagnosis.

“I hear this all the time,” Vila said. “Patients are told, ‘You’re getting older, you’re a woman ... you’re menopausal,’ and so on. That’s not what we do here. I start by looking at the patient’s history, their diet, exercise, sleep patterns and stress levels. Then I move on to blood tests. Almost everyone says they were told that their blood tests were ‘normal.’ But I’m not looking for normal. I’m looking for optimal.

Gary Schulman, a certified fitness trainer who works with clients coping with chronic diseases, including diabetes and arthritis, favors a natural approach to fatigue and warns that people living with stress should not ignore it.

“People say stress can kill you, and they’re right,” Schulman said. “In today’s society, most people are on this disease continuum that I call stress without recovery. They’re dealing with stress from relationships, jobs, the toxins they put on their skin, the toxins they eat. And if they continue on that course, it eventually leads to chronic disease, thyroid problems, high blood pressure and more.”

His recovery plan: cardio workouts with some resistance training (beginning at a rate the client can handle), breathing exercises and stress management. As for diet, he urges clients to eliminate refined sugars and processed foods and limit or eliminate wheat products and refined carbs.

Vila isn’t quite as strict. “I don’t do everything right,” she says, “and I don’t expect people to do everything right. But diet-wise, if you can do 80 percent good and 20 percent bad, that’s a good place to start.”

Coping skills can be taught

Dr. Theophanis A. Pavlou, a pulmonologist focused on sleep medicine at the Sleep Center in Teaneck, N.J., urges anyone with sleep issues to take part in a sleep study. “People can have their doctor order one, as a prescription,” he said.

Such tests can determine whether a person has a disease that can be treated directly or faces a more nebulous situation.

“We’re living in a very complex society,” said Dr. Carlos Rueda, chairman of behavioral health services at St. Joseph’s Healthcare System in Paterson, N.J., “and this causes all kinds of problems. We are dealing with perceived threats from everywhere, economic uncertainty, and we are in constant state of fight and flight. And, of course, people are constantly receiving stimuli from their computers and their phones. You need this if you want to stay competitive but this is also creating constant stress that disrupts sleep and disrupts your circadian rhythm.”

Dealing with these stresses, Rueda said, requires time management skills and relearning how to relax.

“Set a time, say 8 p.m. or 9 p.m., when you turn off your computer and TV screens,” he suggested. “We aren’t supposed to be receiving and processing information 24/7. Stop. Take a pause. Go read a book.”