How COVID-19 Progressed: The March 2020 Picture

Based on the first two large Wuhan case series — published in The Lancet and JAMA in early 2020 — as reported in March 2020. Understanding of the disease has evolved substantially since (new variants, vaccines, treatments), so this is the historical picture, not current medical guidance.

Day 1. Fever, and often fatigue, muscle pain, and a dry cough. A small minority reported diarrhea or nausea one to two days before the fever started. London GP Dr. Clare Gerada, who contracted the virus early, described the beginning as a slight dry cough and tiredness: "Yet it was so mild to begin with, I barely gave it a second thought."

Day 5. Difficulty breathing (dyspnea) — mostly in patients who were older or had pre-existing conditions. In one Wuhan study of 138 patients, about 10% experienced diarrhea and nausea a couple of days before fever and dyspnea appeared.

Day 7. Patients with dyspnea tended to be admitted to hospital around this point. But for the vast majority — about 85% — symptoms began to diminish around day 7. Early guidance was that household members of a symptomatic person should isolate for 14 days from the first person's illness.

Day 8. Patients with severe cases could develop acute respiratory distress syndrome (ARDS) — the lungs failing to supply the body's vital organs with enough oxygen. Roughly 15% of cases reached this stage, according to the Chinese Center for Disease Control and Prevention.

Day 10. Worsening patients tended to enter intensive care around day 10; the average hospital stay in the second Wuhan study was about 10 days.

Day 12. Fever tended to end around this point, according to the first Wuhan study.

This article is general historical information, not medical advice. If you are ill, consult a clinician or current public-health guidance.

Originally published March 2020.