A leaking kitchen faucet can be an annoyance if the dripping is making an irritating noise, but it can also cost you money if the water is leaking out at a significant rate. You could call a plumber to help you with the problem, but you could try to fix it first on your own with a few simple steps. Except for a replacement washer, you probably have the necessary tools on hand.
Turn off the water supply to the faucet. It is usually located under the sink and will look like a wheel or level that you turn.
Turn on the kitchen sink faucet to allow any remaining water to drain out of the faucet.
Plug the sink or lay a towel in the basin to catch any parts that fall as you disassemble the faucet.
Locate the screw that holds the faucet head in place. If you don't see the screw, it might be hidden under a decorative cap. Unscrew the faucet and remove it. Disassemble the faucet head, using the adjustable wrench if needed. Look for the washer, disc mechanism or cartridge.
Replace the washer, disc mechanism or cartridge with a new one. Reassemble the valve and then the faucet in the reverse direction of how you took it apart. Screw the faucet back in place.
Turn the water back on under the sink and then turn on the faucet. Turn it off again and check to make sure the leak is repaired.
If you can't identify the exact type of replacement part you need, take the faucet head to your local hardware or home improvement store and ask for assistance.