Cold
The nose is part of the respiratory system. It is directly connected to the throat and trachea, and ultimately the lungs. As such, there is a possibility that whatever pathogens (viruses, bacteria, fungi, parasites) are infecting the lungs could spread to the nasal cavity and sinuses. This can also trigger the body to produce a thick mucus in the nose, and this thereby becomes a cold. Some cases of pneumonia may start without a cough, sore throat, or cold. It is usually a few days into the pneumonia before a cough, sore throat, or cold, develops. There are also cases wherein, just like in coughs, there is a cold present, but no pneumonia at the start. After a few days of persistent cough or colds, the pathogen could spread to the lungs, and become a case of pneumonia.