iMac responding /running slow

Hi, welcome to the Apple Users Community.

Please try this link for help with your issue

https://support.apple.com/guide/mac-help/if-your-mac-runs-slowly-mchlp1731/mac

Best of luck

We can give more focused answers if you tell us what iMac sub-model including screen size and your OS version. iMacs have been in continuous production for over 22 years and we are very poor at guessing which you have. That information is readily available by doing "About this Mac" for your Apple menu:

For security reasons, please do not post the serial number.

Please read the following user tip and restate your question/problem in detail: 

Writing an Effective Apple Support Communities Question - Apple Community