How will having chiari syndrome mess up my health later in life?

Probably won't. A type 1 chiari malformation is usually asymptomatic, but on occasion may cause symptoms such as headaches or sensory changes in the face or arms. Chiari's are often discovered incidentally when someone is being worked up for headache or other neurologic symptoms that are unrelated. Unless you have specific related symptoms, then it should cause you no complications later in life.