WordPress theme causing high cpu usage

[First-Dragon]

Hello, i have a problem on my WordPress site, it is using 90% of CPU all the time and creating high load. When i activate to default WordPress theme cpu usage is normal and there is no load, but when i switch back to my cutom made theme CPU usage immediately jump to 90%.
If someone can help me fix this, what error should i look for in my theme, what can cause this problem, i mean what part of theme functions.php or maybe some scripts etc?
Thanks.

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Update: When i remove categories from sidebar CPU load is normal, when i put them back CPU usage high again.

 

[showstopper]

1 . Find another theme
2. try placing categories as a dropdown

the list goes on but try those and see how things work

 

[Claudiu]

Did you check the error logs of your http server?

 

[Akelu]

sistesha travelled

may be some plugins using too much resources!!! try to disable all then activate 1 by 1...

 

[Loonycgb2]

If it is from a category code then you are facing a badly coded php+mysql code.

Please post the category code and any other code linked to it.

 

[First-Dragon]

The load was caused by post count showing for every category, when i disabled post count in categories everything back to normal. My guess is this can cause problems only if you have a big number of posts like i have. Thought someone might find this useful if facing similar problem.