A cylinder misfire is a serious problem that needs fixed as soon as possible.
When a cylinder is not firing correctly it can do internal damage to your engine requiring complete engine replacement or engine rebuilding if the cylinder misfire is not corrected.
A cylinder misfire can also cause loss of engine power.
Things that could cause cylinder misfires are bad ignition coils, bad, worn or damaged spark plugs, bad spark plug wires and if your vehicle is equipped a bad distributor rotor or distributor cap could cause weak spark and cause a cylinder misfire.
If your timing chain or timing belt is worn or stretched and your ignition timing gets off then it can also cause cylinder misfires which can damage your engine.