My mother is suffering from elergy..her problem starts with summer season. .since 20 years..she can't even breath proprly. please tell me some solution?

Allergic : She could use otc antihistamines or nasal steroids , if she cannot breathe, should be checked for a surgically correctable nasal block by an ear nose throat doc.

Sounds complex.: Basics of treatment would include a non sedating antihistamine with consideration of additional agents such as steroids ( nasal, inhaled) antihistamines ( for eyes) and albuterol or montelukast if circumstances warrant.