What will happen if you skip a dialysis treatment?

Can lead to death. Dialysis is a way of filtering out the toxic wastes in blood and removing excessive fluid in body. Cummulation of potassium at high level can lead to irregular heart beats and even to cardiac arrest.
Not a good idea! The normal kidney works 24 hours a day. Think about it, skipping dialysis is like 'cleaning" the blood intermittantly, which can lead to ill effects.