Analysis of data reveals that there are six distinct ‘types’ of COVID-19, each distinguished by a particular cluster of symptoms. The types also differed in the severity of the disease and the need for respiratory support. Launched in the UK and extended to the US and Sweden, the COVID Symptom Study app asks participants to log their health and any new potential symptoms of COVID-19 on a daily basis. This study was the largest of its kind in the world with more than 4 million users.
Continuous cough, fever and loss of smell (anosmia) are usually highlighted as the three key symptoms of COVID-19, however, data shows that people can experience a wide range of different symptoms including:
- Muscle pains
- Loss of appetite
- Shortness of breath
- And more! *
An analysis of the symptoms revealed six specific groupings of symptoms representing six distinct “types” of COVID-19. All people reporting symptoms experienced headaches and loss of smell, with varying combinations of additional symptoms at various times. A CBS News article summarizes the six clusters are as follows:
- ‘flu-like’ with no fever: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever
- ‘flu-like’ with fever: Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite
- ‘gastrointestinal’: Headache, loss of smell, loss of appetite, diarrhea, sore throat, chest pain, no cough.
- ‘severe level one, fatigue’: Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue
- ‘severe level two, confusion’: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.
- ‘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, diarrhea, abdominal pain.
Broadly, people with cluster 4, 5 or 6 COVID-19 symptoms tended to be older and frailer and more likely to be overweight and have pre-existing conditions such as diabetes or lung disease than those with type 1, 2, or 3.
What does this mean to us? It is unclear except that symptoms vary widely so if you have symptoms, self-isolate, get tested if possible and take care of yourself! Stay well, stay safe and stay tuned!
*Of note, the COVID Symptom Study has also identified skin rash as a key symptom of COVID-19 in up to one in ten cases. That said, it is not recognized as a symptom during the time this data was gathered so is currently unknown how skin rashes map on to these six clusters.