The dosages need to be based on the illness treated, your past and present medical history, your age, your weight, and several other factors. Combinations must be chosen so as not to interfere with any specifics with your particular body, and so as not to further aggravate that which is being treated. A health care professional can help you choose the proper combinations and dosages for your unique body and health concerns. You wouldn't hide the fact that you are a smoker or a drinker or have a heart condition from your physician. You shouldn't hide the fact that you are using herbal medicines, either.
Some herbs can have serious adverse reactions when improperly mixed with prescription drugs.
Many chemical drugs are derived from healing plant constituents. So you could be causing a serious problem for yourself if you are getting far too much of something that is supposed to be helping you. There is no reason to hide. Herbal healing is becoming much more mainstream today, and many physicians are learning about herbs as medicine. If yours isn't, then help educate him or her.