Sinus tachy??

Im 16 turning 17 soon and im a female and a doctor told me i had sinus tachy.
I want to know what i should stay away from and what would be good for someone who has sinus tachy?
is there a cure for sinus tachy? do you grow out of it?
is it something i should be worried about?
I know not to drink alchohol or have coke or coffee but what else?
I try to drink as much water as i can but i can be stubborn sometimes.

[kenkeith]

For some insight: Sinus tachycardia occurs in response to exercise, exertion, excitement, pain, fever, excessive thyroid hormone, low blood oxygen (hypoxia), stimulant drugs (such as caffeine and amphetamines), etc.  Did you have an EKG test? All of the above possible causes would have to be ruled out before there can be a serious heart problem diagnosis.  

The probability is high that there is no serious medical problem.