A cold is an upper respiratory viral infection. While the same virus does not transform into pneumonia, a cold can sometimes weaken the airways enough for a secondary infection, such as bronchitis or pneumonia, to take hold lower in the chest.
Warning signs that the illness may have moved to the chest include a cough that worsens or produces discoloured phlegm, a high or returning fever, chest pain, rapid breathing, or shortness of breath. Feeling much more unwell several days into a cold is a red flag.
Older adults, young children, smokers, and people with asthma, COPD, heart disease, or weakened immunity are at higher risk and should seek advice early. Call your local emergency number for severe breathing difficulty, chest pain, confusion, or bluish lips.