As the name suggests, deep tissue massage applies deep pressure onto specific trouble points. It is higher than normal pressure focused by pushing into your knotted muscle. The massage can sometimes leave you feeling sore. It's not just more pressure over the entire body, it's a very specific, methodical treatment. The therapist uses knuckles, elbows, and forearms to "strip out" muscle tissue as far down to the bone as possible.
This modality can be helpful to the following people: athletes who are harder than average on their bodies, people who are undergoing physical therapy to aid in the breakdown process of scar tissue, or anyone who has very dense tissue and responds better to this style work.
It is very important to ALWAYS speak up and let your therapist know if you need to correct the pressure. (i.e. if you need them to lighten up because it is too deep, or to apply more because it is not deep enough).
Most everyone needs more pressure in some areas and less in others. This mainly occurs because muscle tissue that contains Trigger Points are more sensitive to pressure and can be tender to the touch.