Usually drains are clogged because people are not careful of what they put in them, especially in the kitchen.
Other drains, like in the bathroom, get clogged because of the oil residue from soaps, shampoos and hair. It is recommended that you are conscious of what you put down your drains and treat them regularly with a drain cleaner such as Total-C.
There is a possibility that the piping is worn out or, unfortunately, plumbed incorrectly. It is necessary to have this examined by one of our well trained technicians. They will determine the problems with your drains and offer you the best options for repair.