Imagine living with a disease that renders you disabled and exhausted, unable to meet the physical demands of daily living. Now imagine that much of the medical establishment refused to believe your disease was "real" in the sense of a physical illness and failed to fund research into its true causes and treatment.

That's the situation of the more than 1 million people in the US living with myalgic encephalomyelitis/chronic fatigue syndrome, or ME/CFS. The disease causes crippling exhaustion, particularly after exercise, as well as pain, nonrestorative sleep, and other issues. It often, but not always, arises suddenly after an illness like the flu. Science still can't explain what causes it or offer useful treatments.

In fact, up to this point, research has arguably done ME/CFS patients more harm than good.

As Julie Rehmeyer, herself an ME/CFS patient, reported in STAT, a bad 2011 study known as the PACE trial suggested that the disease was psychological and should be treated with cognitive behavioral therapy and exercise. That research, it turns out, was based on faulty methods and suggested interventions that might have made people's symptoms worse, not better. But it took patients until 2015 to prove it.

Also in 2015, the Institute of Medicine published a highly anticipated report concluding that "ME/CFS is a serious, chronic, complex, systemic disease that often can profoundly affect the lives of patients." The report estimated that 836,000 to 2.5 million Americans were suffering from it and said "misconceptions or dismissive attitudes on the part of healthcare providers make the path to diagnosis long and frustrating for many patients."

But ME/CFS has a history of being dismissed and ignored, and a culture had already developed of not taking the disabilities of people with the disease seriously. Little funding flows toward ME/CFS research.

As the Institute of Medicine report noted, "Remarkably little research funding has been made available to study the cause of ME/CFS, mechanisms associated with the development and progression of the disease, or effective treatment, especially given the number of people affected."

'It's almost impossible to get anyone to pay attention to this disease'

That's why several dozen patients and allies gathered outside the Health and Human Services office in New York City on Tuesday to demand more funding and attention for the disease. Many leaned on light poles, sat on the ground, or sat in wheelchairs throughout the protest. Several used video chat to attend virtually from their beds.

It was one of several similar scenes playing out in cities across the country as part of the #MillionsMissing protest network.

"This is the first time I'm really meeting other patients with ME, because we all are so isolated from each other," Paris Abell, a corporate lawyer with ME/CFS who attended the protest, told Business Insider. "It can take so long to get a diagnosis and then you're just focused on your day-to-day function and then you're just trying to go on living every day. And it's almost impossible to get anyone to pay attention to this disease or take it seriously."

Speakers told stories of suddenly losing their mobility and the physical stamina to meet the demands of everyday life. They described going years without diagnoses and the sense that "chronic fatigue syndrome" is a name used to imply people with a physical disease are mentally ill.

Activists from Act Up, an organization founded in the 1980s to demand attention and funding to combat AIDS at a time when the government was largely unwilling to acknowledge it, joined the small protest to express their support.

In the more than a year since the PACE trial, there has been some forward motion on the disease. Researchers, some of whom attended the protest, have begun to take ME/CFS seriously. And 55 members of Congress recently sent a letter to the National Institutes of Health requesting that the agency take on ME/CFS as a national medical problem.

But progress remains slow, as the recent Institute of Medicine report made clear, arguing that "more research is urgently needed."

At the end of the protest, activists carried a giant "report card" covered in facts about ME/CFS up the steps of the Health and Human Services building. The grades: all Fs.