Loose or badly fitting kitchen cabinet doors are a common problem.
Most cupboards these days use a concealed steel hinge which are sprung so the door stays closed without the need for any catch. They are fairly easy to adjust if you understand how they work.

Whilst various brands will vary slightly essentially they come in two parts one screws to the door with two door holding screws. The other part screws to the cupboard frame with two cupboard holding screws.

They slot together and are held in place with a locking screw which tightens up to hold the door in place. Some more modern hinges also have a sprung loaded quick release catch so you can remove the door simply by pulling back the catch.
Finally there is and adjusting bolt which is used to move the door left and right, or change the angle.

How to adjust cabinet doors
Common problems

1 Make sure the locking screw C is tight. If this has come loose the door may have slid in or out from its original position as the two parts of the hinge slide against each other. When the door is open as shown aim for approx. a 1mm gap between the door and the cupboard.

2 If this doesn't fix the looseness check the fixed door screws A and the adjustable cupboard screws B Tighten these up. If they won't tighten you may need to discard the original screws and replace them with fatter or longer ones. Make sure longer ones aren't so long that they go right through the wood. Sometimes you may need to fill the holes with good quality two part wood filler to get a good tight connection. (if using filler drill a pilot hole before screwing back in to the filler)

Having made sure the doors aren't loose you can if necessary then make small adjustments if they aren't properly aligned.

Adjusting badly aligned doors

1 To change the vertical height . Undo the two adjustable cupboard screws B on both hinges.
They are usually in slotted holes which mean and you can adjust up or down by a few mm. Then tighten back up

Binding door

If the door is not closing properly or is making creaking sounds it may be binding on the cupboard frame.

Look on the side where the hinges are as you close the door. The door may be touching the cupboard frame as it closes.(binding) To stop this you need to adjust the door out towards you slightly. Unscrew the locking screw C on both hinges. The door can now slide in and out a little. Pull it towards you slightly and re-tighten.

The ideal gap need not be any more than 1mm.