Elderflower - sambucus nigra - or elderberry - is a traditional remedy that’s been used medicinally for hundreds of years to treat flu, allergies and boost the health of the respiratory system. Elderflower is used for swollen sinuses (sinusitis), colds, influenza (flu), swine flu,bronchitis, diabetes, and constipation. It is also used to increase urine production (as a diuretic), to increase sweating (as a diaphoretic), and to stop bleeding. Elderflower is also used as a gargle and mouthwash for coughs, colds, hoarseness (laryngitis), flu, and shortness of breath. It is used on the skin for joint pain(rheumatism), and pain and swelling (inflammation).Some people put elderflower in the eyes for red eyes.In combination with gentian root, verbena, cowslip flower, and sorrel, elderflower is used for maintaining healthy sinuses and treating sinusitis.In foods and beverages, elderflower is used as a flavouring component.