The symptoms of COVID-19 are variable and often include one or more of the following:
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue
- Headache
- Nasal congestion or runny nose
- Muscle or body aches
- Sore throat
- New loss of smell or taste
- Nausea or vomiting
- Diarrhea
Symptoms may begin one to fourteen days after exposure to the virus. Approximately a third of individuals who are infected do not develop noticeable symptoms. For those individuals who develop noticeable symptoms, about 81% will develop mild to modest symptoms, while 14% will develop severe symptoms, such as dyspnea and hypoxia, and 5% will have critical symptoms, such as respiratory failure, shock, or multiorgan dysfunction. Moreover, older people are at a higher risk of developing severe symptoms. Multiyear studies are currently underway to determine the long-term effects of COVID-19.
It should be emphasized that most COVID-19 illnesses are mild, and most patients, especially children and young adults, tend to recover spontaneously if given supportive care. Since COVID-19 is a relatively new disease, there is limited information regarding risk factors for severe disease. Some cases can lead to serious illness with difficulty breathing, which may lead to death. Currently, older people tend to have a higher risk of severe disease, and individuals of all ages with underlying medical conditions, such as heart disease, diabetes, or lung disease, may also be at higher risk of developing severe COVID-19.
