The risks associated with Chiropractic treatment although rare but can be serious are.
Worsening of existing problems such as a herniated disk problem, Compression of your nerves which exist in the lower spinal column and even a certain type of stroke can be caused by Chiropractor treatment which is called Vertebral artery dissection.
These conditions and risks are rare but do happen. I wouldn't worry too much since going to a Chiropractor has more benefits than risks.