Never ignore a refrigerator when it's acting up in any way; a small problem can soon lead to a complete shutdown of this appliance, and all the groceries inside may spoil while you're waiting for a repairperson. Seemingly small problems can also mean that the air inside the appliance is struggling to stay cool; this can cause the motor and blower to work harder than they should, so they may fail sooner rather than later. Note a few problems you may notice with a faulty refrigerator and their potential causes so you know what you may be facing by way of needed appliance repairs.
If the doors of the refrigeration hold condensation or feel damp to the touch, this usually means cold air is escaping from inside the fridge and is hitting the warmer air outside, allowing that condensation to form. Cold air usually escapes from the refrigerator when the doors are not closed and sealed properly. The gaskets around the doors are the first things to check; these are the rubber pieces that are attached to the edge of the door, and they're meant to create an airtight seal. If these gaskets are old and soft or are cracked and split, they won't cling to the refrigerator itself and will then fail to seal in that cooler air.
Another cause of a door not sealing or closing properly is a worn hinge. An older hinge can allow the door to swing away from the refrigerator or freezer compartment slightly so that air escapes. If the gaskets appear to be fine, replace the hinges on the door and note if this keeps it shut firmly.
A refrigerator works by collecting air from the room around it and from inside the fridge, which it then circulates over a refrigerant. A piece called a compressor squeezes or compresses that refrigerant to make it cold, so it can properly cool that air. This compressor should work very quietly; however, when it begins to break down, you may hear a thumping or banging sound as it tries to squeeze and press that refrigerant. You may also notice that the inside of the refrigerator is too warm, and the compressor usually then needs replacing.
If the sound you hear is more like a grinding, this often means the fan of the refrigerator is failing. When the compressor and refrigerant cool the air pulled in from the room around it, the fan pushes that air into the refrigerator. When the fan begins to fail, its motor may begin to grind, and it may also need replacing.