In the U.S. alone, more than 100 million people have been infected with SARS-CoV-2, the virus that causes COVID-19. Many who were diagnosed with COVID experienced mild and/or brief symptoms — but certainly not everyone.

As of this spring, the federal government estimates that 60,000 people (6 percent) are still experiencing one, or more, of COVID’s symptoms. This condition is known as long-COVID. New research that looked into the symptoms of long-COVID and categorized them for the first time, was just published in JAMA, the Journal of the American Medical Association.

The study, which included nearly 10,000 participants, is known as RECOVER, an acronym standing for Researching Covid to Enhance Recovery. The research is ongoing and will take place over four years with a price tag of $1.15 billion. Funded by the National Institutes of Health, it’s expected to be able to help standardize not only the definition of what long COVID is, but also make a significant impact on how the condition is studied and how it is treated. RECOVER has already identified 12 of long-COVID’s key symptoms. And that’s a big deal because it’s never been done before.

It’s expected that the definition of long COVID will continue to evolve, but having a working definition is a “huge first step.”

“If you look up simple questions like ‘how many people get long COVID,’ the answers are all over the place because people define it differently,” Leora Horwitz, a physician and co-principal investigator for RECOVER Clinical Science Core at NYU Langone Health, said in a press statement.

To help clarify the symptoms of long COVID, as well as identify them, the study used a point scoring system based on how likely the symptom was a true signal of long COVID versus some other condition. For example, when researchers analyzed self-reported symptoms, they found that some were more common in people who were infected, but were less common in those folks who never had COVID. An example of this would be loss of taste or smell.

In order for participants to meet the definition of long COVID, they needed to score a total of 12 points once all their symptoms were tallied.

Here are the 12 key symptoms and their corresponding scores:

  • Loss of smell or taste — 8 points
  • Post exertional malaise — 7 points
  • Chronic cough — 4 points
  • Brain fog — 3 points
  • Thirst — 3 points
  • Heart palpitations — 2 points
  • Chest pain — 2 points
  • Fatigue —1 point
  • Dizziness — 1 point
  • Gastrointestinal symptoms — 1 point
  • Issues with sexual desire or capacity — 1 point
  • Abnormal movements (including tremors, slowed movements, rigidity, or sudden, unintended and uncontrollable jerky movements) —1 point

“This offers a unifying framework for thinking about long COVID, and it gives us a quantitative score we can use to understand whether people get better or worse over time,” said Tanayott Thaweethai, the study’s lead author and a researcher at Massachusetts General Hospital and Harvard Medical School. “Higher symptom scores also correlated with a lower quality of life.”

Participants needed to score a total of 12 points once all their symptoms were tallied to meet the definition of long COVID.

This isn’t the end of the story. Researchers stress that their findings are still preliminary and it’s still too soon to use the symptom list, or its scoring system, to diagnose long COVID or to determine a person’s eligibility for disability benefits.

It’s expected that the definition of long COVID will continue to evolve and be refined by the researchers. But, still, having a working definition is a “huge first step,” according to Horowitz. The next step is for the researchers to validate the study results and then compare them against lab tests and imaging.

Meanwhile, if you’ve been experiencing what you believe to be long-term COVID symptoms, the Centers for Disease Control (CDC) suggests seeking advice from a healthcare provider who will come up with a personal medical management plan that can help improve your symptoms and your quality of life.