A common symptom of a cold is a blocked (congested) nose. A stuffy, blocked-up feeling in your nose can also occur in the absence of a cold. This is because the inside lining of your nose is sensitive to changes in the atmosphere (such as temperature and humidity changes) and this also can lead to symptoms of nasal congestion.
This is a companion discussion topic for the original article at https://patient.info/medicine/ephedrine-for-nasal-congestion