If it is clogged by items from the freezer,. Open the freezer and make sure that nothing blocks the defrost drain along the back wall. If it's obstructed by items in the freezer, simply move things around until air can flow freely and then wait a day or two to see if the problem has been resolved. If puddles persist, something smaller, such as crumbs or ice, may be causing the blockage.
In any of these cases, you will have to transfer the food from the fridge and freezer to a mini fridge or horizontal freezer and unplug the refrigerator. Then remove the plastic plate above the drain hole (the appliance manual may have advice on this) and use a turkey sprayer or funnel to drop the hot water down the defrost drain. This should clear the drain of debris and allow the unit to function normally again. Common solutions To fix the problem, try to melt the ice.
To do this, place warm water in a turkey syringe or similar container. You'll pour the water down the freezer drain. If this doesn't work, some people try using a pipe cleaner or wire hanger to break the ice. If the blockage is too low in the hose, you may have to move the refrigerator and disconnect the valve.
A professional will examine the condition of the appliance to determine if it needs a new refrigerator or repair.