People suffering from blocked noses have been advised to limit their use of nasal decongestant sprays to a maximum of five days or risk exacerbating the problem. The Medicines and Healthcare products Regulatory Agency (MHRA) has imposed this restriction, warning that excessive use can lead to "rebound congestion" and other "adverse effects following prolonged use". These sprays, which offer short-term relief from stuffiness caused by colds, allergies, and sinusitis, contain xylometazoline and oxymetazoline. While new packaging and leaflets will eventually state the five-day usage limit, the regulator noted that these changes will take months to implement. Patients are therefore urged to follow the updated guidance immediately, even before product information is revised. All new packaging and leaflets for such sprays and drops will now state the duration of use is not to exceed five days.…