Can antihistamines relieve a runny nose?

When runny nose is caused by allergic rhinitis, antihistamines can help relieve the symptom. However, if the runny nose is caused by a cold, influenza, or other non-allergic factors, antihistamines generally cannot directly alleviate the runny nose. Antihistamines should be used rationally under a doctor's guidance, and attention should be paid to related adverse reactions and precautions. The analysis is as follows:

Antihistamine medications have anti-allergic effects, primarily functioning by blocking the binding of histamine to receptors and producing antibodies, thereby relieving symptoms such as runny nose. If the runny nose is caused by allergic rhinitis, which leads to inflammatory reactions in the nasal mucosa and increased secretions, antihistamines can reduce edema and inflammation of the nasal mucosa, thus alleviating symptoms such as runny nose and sneezing.

If the runny nose is due to a cold, flu, or other non-allergic causes, antihistamines may not effectively relieve the symptom. In these cases, the runny nose is mainly caused by viral infection or upper respiratory tract infection, rather than histamine activity. Using antihistamines may not improve symptoms and could, at times, even cause discomfort due to the drug's side effects.

After taking antihistamines, patients may experience adverse reactions such as sedation, drowsiness, fatigue, weakness, and dizziness. Therefore, individuals engaged in work requiring high concentration are advised not to take this medication before working.