Lemna Minor Is a catarrhal remedy. Lemna Minor acts especially upon the nostrils. Nasal polypi; swollen turbinates. Atrophic rhinitis . Asthma from nasal obstruction; worse in wet weather. Chronic sinusitis is a condition in which the sinuses inside our skull become inflamed for months and years together. This condition can considerably reduce ones quality of life. Patients suffering from chronic Sinusitis complain of difficulty in breathing from nose, headaches, pain and tenderness in the face. 
Conditions that can cause sinus blockage include the common cold , allergic rhinitis (swelling of the lining of the nose), nasal polyps (small growths in that lining), or a deviated septum (a shift in the nasal cavity). 
Lemna Minor works well in cases where the sinusitis is complicated by nasal polyps. 

Use under medical supervision.