November 2020
Aria Bendix
As doctors observe a growing number of coronavirus patients, they've identified a few patterns in how typical symptoms progress.
As many as 40% of coronavirus cases are asymptomatic, according to the Centers for Disease Control and Prevention. And only 20% of symptomatic cases become severe or critical.
Among patients who develop symptoms, a fever and cough are usually the first to arrive. They're often followed by a sore throat, headache, muscle aches and pains, nausea, or diarrhea (though in severe cases, gastrointestinal issues can appear earlier in the course of an infection). Patients with severe infections tend to develop difficulty breathing — one of the virus' hallmark symptoms — around five days after symptoms start.
But symptoms generally don't appear right after a person has been infected. The virus' median incubation period is about four to five days, according to the Centers for Disease Control and Prevention. During that time, an infected person likely won't yet know they're sick, but evidence shows they could transmit the virus during the presymptomatic phase.
