Researchers have identified six types of coronavirus — a breakthrough for treatment that could help healthcare providers predict the most vulnerable cases.

Each type has a specific set of symptoms, which is believed to help determine the severity of cases, how fast the disease would progress and whether they will need respiratory support.

Symptoms not often linked to coronavirus, such as abdominal pain and confusion, were found to be common among severe cases.

Researchers from King's College London (KCL), who led the study, said this breakthrough could save lives during the predicted second wave of COVID-19.

"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 hospitalisations and saving lives,” said KCL’s Claire Steves.

According to the study, symptoms go beyond the common consistent cough, fever and loss of smell. People have been reported to experience headaches, confusion, fatigue, muscle pain, loss of appetite, shortness of breath and diarrhoea, among other symptoms.

The six symptom clusters of COVID-19 were identified by KCL as the following:

1. ‘Flu-like’ with no fever: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever.

2. ‘Flu-like’ with fever: Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite.

3. Gastrointestinal: Headache, loss of smell, loss of appetite, diarrhoea, sore throat, chest pain, no cough.

4. Severe level one, fatigue: Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue.

5. Severe level two, confusion: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.

6. Severe level three, abdominal and respiratory: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain, shortness of breath, diarrhoea, abdominal pain.

Researchers found patients in need of respiratory support stood at 1.5% of those displaying the first clusters of symptoms, 4.4% of patients with the second cluster of symptoms and 3.3% for patients with cluster three symptoms.

However, 8.6% of cluster four needed breathing support, 9.9% for cluster five and 19.8% for cluster six.

Approximately half of cluster six required hospitalisation, in comparison to 16% of the first cluster.

Patients in cluster four, five and six were often of older age, overweight and had underlying health issues.

Findings proved the importance of using the mobile application, as it is "helping us to stay ahead of any local hotspots or a second wave of infections", said KCL’s Professor Tim Spector.