More than 90 percent of upper respiratory infections are caused by viruses. These infections create different symptoms at each stage. Most colds and flus go away in about a week, although some symptoms (like coughing) can take two or three weeks to go away completely.
Helen (Eleni) Xenos, a One Medical doctor in Chicago, describes the typical progression of the common cold:
- Day 1: Fatigue, headache, sore or scratchy throat.
- Day 2: Sore throat worsens, low fever, mild nasal congestion.
- Day 3: Congestion worsens, sinus and ear pressure become very uncomfortable. It may be difficult to sleep.
- Day 4: Mucus may turn yellow or green (this is normal). Sore throat improves, but coughing begins.
- Days 5-7: Energy and congestion improve.
- 1 week+: Cough usually tapers off after a week, but can take up to 3 weeks to fully resolve.
If your symptoms are much worse than these, such as coughing so hard you throw up, or coughing up bloody mucus, or if you have a fever over 102°F, you might have something more serious going on, like pertussis (whooping cough) or pneumonia.