Yes, it is very important. Our bodies are made up of approximately 70% water. If properly hydrated, the tissue will move more freely during your treatment making it less painful.
Experts give a basic guideline for daily water consumption as follows: Take your body weight in pounds and divide it by two to get the recommended ounces per day. If you enjoy any de-hydrating beverages (coffee, soda, alcohol, etc.) then add another 8 ounces per serving.