Sudin Nd 0.1 % Nasal Drop is used for relieving nasal blockage caused by common colds, sinusitis, hay fever, and other upper respiratory allergies. Its active ingredient, Xylometazoline (0.1%), works by stimulating alpha-adrenergic receptors in the nasal blood vessels, causing them to constrict, which reduces swelling and inflammation. This action opens up the nasal passages, eases breathing, and promotes sinus drainage. It provides temporary relief from stuffy nose, congestion, and discomfort, helping restore free breathing. The localised effect minimises rebound congestion when used as directed.