Share ISA trading and tax?

Hi everyone :)

I am a full time trader currently trading within my share ISA.

I have grown £10k into £50k in the last 12 months day trading small cap companies listed on LSE, on average I buy and sell one stock a day.

I do not plan to withdraw money into my bank account as I want to build my ISA account substantially, I have however taken a few £1000 out to pay for a few items here and there.

I am unsure on the situation regarding tax is, I know ISAs are tax exempt from CGT and income but as I have built it quite alot I do not want HMRC getting funny.

So I guess my question is do I have to pay any tax if I continue growing my ISA account exponentially? and for hearsay do I even have to pay tax if I started withdrawing monthly amounts to my bank account?

It is all very confusing to me.

Thanks for any help :thumbsup:

Share ISA trading and tax?