These three illnesses share many symptoms, which makes them hard to separate by feel alone. A common cold usually builds up slowly, centered on a runny or blocked nose, sneezing, and a mild sore throat, often without much fever. Flu tends to start abruptly with high fever, body aches, headache, and exhaustion that can put you in bed. COVID-19 can resemble either and may include cough, fever, sore throat, fatigue, and sometimes loss of taste or smell.
Because the overlap is large, a COVID-19 test is the most reliable way to confirm or exclude it, which matters for protecting others. Most cases of all three are managed at home with rest, fluids, and symptom relief recommended by a pharmacist.
Seek urgent care if you have difficulty breathing, chest pain, persistent high fever, confusion, or bluish lips, or if symptoms rapidly worsen. People who are older, pregnant, or have chronic conditions should seek advice earlier, as antiviral treatment may help. This is general information only.