Your A/C may be suffering from a lack of air flow as a result of bent or otherwise damaged coil fins. For more information, please review the following handy diagnostic article:

http://yourhandymanzone.com/Your_Handyman_Zone_How_To_Pages_Home_Improvement_Zone_Cooling_Ventilation_Systems_Central_Air_Conditioning_Coil_Fins_Bent_Prevent_Air_Flow.htm

While your description is quite broad, I hope this helps.

Good luck!

Brad