What can i do about a constant dry mouth? why does this happen?

Moisture seeker: Dry mouth causes include meds, aging, allergies, radiation therapy or autoimmune disease such as sjogren's syndrome. Try sugar free candy or gum, frequent sips of water, biotene or oasis dental products. Make sure you see your dentist regularly as dry mouth can cause severe dental disease. Sjogren's affects all mucous membranes and the eyes too. If this is you then see a rheumatologist.

Control: One of the major causes of dry mouth is the medications that you are taking so all you can do is control it and the damage dry mouth does to teeth. Avoid mouthwash with alcohol. Biotene make some great products for dry mouth. Use xylitol or sugar free gum and mints. Avoid sugary and acidic food and drinks. Get mi paste from your dentist. Regular dental care. Brush and floss. No smoking.