A new study led by researchers from King’s College London has tapped into data of 1,600 patients from a symptom tracker app to reveal that there are six distinct “types” of COVID-19, each distinguished by a particular cluster of symptoms.

The researchers’ findings, which have not been peer-reviewed, claim that the six different “types” of the contagion can vary by severity and unique symptoms.

“Our study illustrates the importance of monitoring symptoms over time to make our predictions about individual risk and outcomes more sophisticated and accurate,” lead researcher Dr. Carole Sudre, of King’s College London, said in a release.

“This approach is helping us to understand the unfolding story of this disease in each patient so they can get the best care.”

The first type is “flu-like with no fever,” and this usually comes with headaches, loss of smell, muscle pains, cough, sore throat and chest pain. Patients at this level have a 1.5% chance of eventually needing breathing support like a ventilator.

The second—“flu-like with fever”—includes symptoms like loss of appetite, headache, loss of smell, cough, sore throat, hoarseness and fever. Over 4% of patients will need breathing support.

The third type is simply described as “gastrointestinal,” and these patients do not have a cough, but they do experience headaches, diarrhea, loss of smell, loss of appetite, sore throat and chest pain. Just over 3% will need breathing support.

Patients with the fourth type, also called “severe level one,” often experience fatigue along with headaches, loss of smell, cough, fever, hoarseness and chest pain. There is an 8.6% chance that they will need breathing support.

The fifth type is called “severe level two,” and this can include the symptoms of type four along with loss of appetite, sore throat and muscle pain. This particular type is chiefly distinguished by confusion, and about 10% will need breathing support.

The sixth type is known as “severe level three,” and this comes with all the symptoms of type five along with abdominal pain, shortness of breath and diarrhea. As the most serious type, nearly half of these patients will require hospitalization and 20% will need breathing support.

“These findings have important implications for care and monitoring of people who are most vulnerable to severe COVID-19,” Dr. Claire Steves, of King’s College London, said in a release.

“If you can predict who these people are at day five, you have time to give them support and early interventions, such as monitoring blood oxygen and sugar levels, and ensuring they are properly hydrated—simple care that could be given at home, preventing hospitalizations and saving lives.”

There are now more than 16.3 million confirmed cases of coronavirus worldwide, including at least 650,000 deaths, according to the latest data from Johns Hopkins University.

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. Follow or contact him on LinkedIn.