Symptoms of a cold can be felt about 1-4 days after catching a cold virus. They start with a burning feeling in the nose or throat, followed by sneezing, a runny nose, and a feeling of being tired and unwell. This is the period when you are most contagious -- you can pass the cold to others -- so it's best to stay home and rest.
For the first few days, the nose teems with watery nasal secretions. Later, these become thicker and darker. You may get a mild cough. It won't get much worse, but it is likely to last into the second week of your illness. If you suffer from chronic bronchitis, a cold will make it worse.
Dark mucus does not necessarily mean that you have developed a bacterial infection, but if you are coughing up dark material -- or feeling a lot of distress low down in your lungs -- you may have a bacterial infection. These symptoms can also be caused by a cold virus other than a rhinovirus.
Usually there is no fever; in fact, fever and more severe symptoms may indicate that you have the flu rather than a cold.
Cold symptoms typically last for about three days. At that point the worst is over, but you may feel congested for a week or more.
Except in newborns, colds themselves are not dangerous. They usually go away in four to 10 days without any special medicine. Unfortunately, colds do wear down your body's resistance, making you more susceptible to bacterial infections.
If your cold is nasty enough, seek medical attention. Your doctor likely will examine your throat and ears. He or she may take a throat culture by brushing the throat with a long cotton-tipped swab. This will show whether you have a bacterial infection, which requires treatment with antibiotics.
Call Your Doctor About a Cold If:
You notice an inability to swallow
You have a sore throat for more than two or three days, particularly if it seems to be worsening