Is pulmonary edema a circulation problem?

Sort of. Pulmonary edema can be related to heart failure. If the heart fails as a pump, this elevates the blood pressure in the pulmonary circulation, because the fluid gets "backed up", the elevated pressure causes the capillaries to leak fluid into the air spaces. In non cardiac edema, there is an inflammatory injury to the capillaries, from a toxin or infection etc.. This causes the capillaries to leak.