British scientists analysing data from a widely-used Covid-19 symptom-tracking app have found there are six distinct types of the disease, each distinguished by a cluster of symptoms. The King's College London team found that the six types also correlated with levels of severity of infection and with the likelihood of a patient needing help with breathing - such as oxygen or ventilator treatment - if they are hospitalised. The study, released online on June 16 but not peer-reviewed by independent scientists, described the six Covid-19 types as: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever. Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite. Headache, loss of smell, loss of appetite, diarrhoea, sore throat, chest pain, no cough. Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue. Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain. Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain, shortness of breath, diarrhoea, abdominal pain.