| Symptoms | Cold | Influenza | Pneumonia | Sinus Infection |
| Fever | Rare | Characteristic high (100.4-104 °F). Sudden onset lasts 3-4 days. | May or may not be high. | Rare |
| Headache | Occasional | Prominent | Occasional | Prominent, with pressure in the face |
| General aches/pains | Slight | Usual; often quite severe. Extreme; can last up to a month | Occasional | Occasional |
| Fatigue and weakness | Quite mild | May occur early and with prominence | May occur depending on type | Not characteristic |
| Exhaustion | Never | Sometimes | May occur depending on type | Not characteristic |
| Runny, stuffy nose | Common | Sometimes | Not characteristic | Postnasal drip, green or gray discharge and congestion |
| Sneezing | Usual | Sometimes | Not characteristic | Sometimes |
| Sore throat | Common | Can become severe | Not characteristic | Not characteristic |
| Chest discomfort, cough | Mild to moderate hacking cough | Severe | Frequent and may be severe | Mild to moderate |
| Complications | Sinus and ear infection | Bronchitis, pneumonia, can be life-threatening | Widespread infections of other organs; can be life threatening, especially in elderly or debilitated patients. | Can be triggered by allergies or develop after a cold |