A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a pressure sensor mounted at a proximal end of a patient line made of a distensible material that provides PD solution to a patient through a catheter. During treatment, an occlusion can occur at different locations in the patient line and/or the catheter. When an incremental volume of additional solution is provided to the patient line while the occlusion is present, a change in pressure results. The change in pressure depends on the dimensions and the distensibility of the non-occluded portion of the patient line. If the change in pressure, the incremental volume, the properties related to the distensibility of the patient line, and some of the dimensions of the patient line are known, the location of the occlusion can be inferred. The occlusion type can be inferred based on the determined location.