Allergies can be incredibly annoying and very serious. Some symtoms may include red eyes, sneezing, shortness of breath, swelling, a runnynose, and more.
What are you allergic to?
From what i remember my doctor said i was generally alergic to the dust and unfiltered air. But some other common allergens are pollen and certain types of food like peanuts.
Are allergies medically related, hereditary or ?
There is a hereditary predisosition to allergies called atopy so it definitely can be hereditary! 
Are they any cure for allergis?
A lot of doctors do things to treat and reduce allergies rather than cure them i have not heard of actually completely getting rid of allergies but redicing the heavy response to them. Unfortunately
So what are the common things people are allergic to?
Reducing* apologize for my typo. Common things are dust, mold, pollen, and for food cow's milk, eggs, fish, tree nuts, soy, rice, wheat, fruit, shellfish, and more and more!
OK ,are you allergic to any of those?