Every year, millions of Americans will go to their doctors complaining of pain, and their doctors will ask them to rate their degree of discomfort on a zero-to-10 scale, or using a range of smiley-face symbols.
The doctor will have to take their word for it. And then, all too often, the doctor will prescribe a powerful and addictive opioid painkiller.
It's a longstanding — if imprecise and subjective — way of measuring and treating pain. And it's at least partly responsible for starting an opioid addiction crisis that killed 64,000 people last year.
"One of the things we heard from many physicians is that the pain-specific indicator contributed to this crisis," said White House Counselor Kellyanne Conway, President Trump's top adviser on the opioid crisis.
"We don't think health care by emoji is good idea," she said.
So the Trump administration, which has declared the opioid crisis a public health emergency, is backing efforts to find better ways of measuring and treating pain in the hope of developing precise treatments that would be more effective than opioids — and without the often catastrophic side effects.
Next month, the National Institutes of Health will open proposals for $4 million in small business grants to develop a device or technology to objectively measure pain. That could take the form of a blood test, a device to measure pupil dilation, or software to interpret facial expressions.
NIH Director Francis Collins calls it the "pain-o-meter."
It's not entirely clear what the pain-o-meter would look like, or exactly how it would work. It hasn't been invented — yet.
But the pain-o-meter isn't meant to be the end game. It's actually the first step in understanding the measurable indicators — or "biomarkers" — that can indicate pain. And that, in turn, could pinpoint causes and treatments, bringing precision medicine to pain management.
"There is this issue about whether we'll ever really get where we want to go in terms of developing effective pain management if we just consider pain to be one thing," Collins told the National Advisory Council for Complementary and Integrative Health last month. "Because we know that it's not."
The current tools of measuring pain don't take into account individual pain thresholds, which can be influenced by genetics, past experiences and other conditions. They often don't distinguish different causes of pain, or different pain sensations.