Each time you get cloned, you generally go back and record a new copy of yourself. Well, if you've ever photocopied a photocopy, you know that after a while, the quality of the copy goes down. This same principle comes into play with your clone. Each time you die and come back as a clone, the chance that you'll contract DCD goes up.
The symptoms of DCD include fever, chills, sweating, lightheadedness, drowsiness, loss of equilibrium, sudden nosebleeds, slurred speech, abdominal pains and fatigue.
There is a cure for DCD, but you'll have to find out about that on your own.