Scientists now have a better understanding of long COVID, or the umbrella term used to refer to the lingering conditions affecting people who previously battled COVID-19. In a new study, they narrowed down the symptoms of the phenomenon to just 12.

In the study published in JAMA Network, researchers presented their definition of post-acute sequelae of SARS-CoV-2 infection or long COVID. The authors noted that they wanted to determine which symptoms were differentially present in patients six months or more after their bout with the virus.

The team analyzed data from 9,764 participants in a prospective longitudinal cohort study and identified 37 symptoms present in patients at six months or more after infection compared with uninfected individuals. The symptoms were determined after the participants answered a survey six months or more after an acute infection.

The researchers made a weighted list of the most commonly reported long COVID symptoms and scored each based on how closely related they are to COVID-19. After narrowing down the list further, the team highlighted only 12 symptoms related to long COVID.

The following are the symptoms of long COVID, according to the new study:

  • Loss of or change in smell or taste
  • Postexertional malaise
  • Chronic cough
  • Brain fog
  • Thirst
  • Palpitations
  • Chest pain
  • Fatigue
  • Changes in sexual desire or capacity
  • Dizziness
  • Gastrointestinal symptoms
  • Abnormal movements

The shorter list is easier to follow than the 200 reported symptoms acknowledged by the World Health Organization (WHO). It can also be used by medical doctors and healthcare professionals in diagnosing patients better.

However, the new study is not free from limitations, similar to other studies of this type. For one, the data used by researchers was self-reported. Hence, the results are open to inaccuracies.

In January, a different study published in the journal Open Forum Infectious Disease also narrowed down long COVID symptoms. From an initial 47, the researchers ended with just seven symptoms.

According to the research team behind it, the most common symptoms of long COVID only included palpitations, fatigue, hair loss, joint pain, chest pain, dyspnea and obesity.

"Despite an overwhelming number of long COVID symptoms previously reported by other studies, we only found a few symptoms specifically related to an infection from SARS-CoV-2, the virus that causes COVID-19," corresponding author Chi-Ren Shyu, the director of the MU Institute for Data Science and Informatics, said at the time.

"Before we examined the data, I thought we would find an ample amount of the symptoms to be specifically associated with long COVID, but that wasn't the case."

The earlier study used data from 17,487 patients diagnosed with COVID-19 in 112 healthcare facilities in the U.S. before April 14, 2022.