Seems the idling system is not functioning well and the possible causes are
1. Vacumn leakages
2. Clogging of Throttle body air passages.
3. Idle Speed Actuator
Is the Check Engine Lamp showing?
It depends on what needs to be done. You can try checking visually for the vacumn leakages. The throttle body and Idle Speed Actuator can be cleaned using a can of carb cleaner.