A negative pressure wound therapy apparatus (400a, 400b, 510) comprising: a negative pressure source (434, 511) configured to couple, via a plurality of fluid flow paths, to a plurality of wound dressings (406a, 406b, 516A, 516B) and provide negative pressure to the plurality of wound dressings, the plurality of fluid flow paths comprising: a first fluid flow path configured to fluidically connect a first wound dressing to the negative pressure source, the first wound dressing with a first fluid retention capacity; and a second fluid flow path configured to fluidically connect a second wound dressing to the negative pressure source, the second wound dressing with a second fluid retention capacity; at least one pressure sensor configured to measure pressure associated with the plurality of fluid flow paths; and a controller configured to operate the negative pressure source, the controller further configured to: receive a plurality of pressure measurements from the at least one pressure sensor; determine from at least some of the plurality of pressure measurements first and second fluid retention capacities of the first and second wound dressings; determine a blockage threshold based at least in part on the determined first and second fluid retention capacities; detect presence of a blockage in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the blockage threshold; and provide an indication of the blockage in response to determining that the blockage threshold is satisfied. a negative pressure source (434, 511) configured to couple, via a plurality of fluid flow paths, to a plurality of wound dressings (406a, 406b, 516A, 516B) and provide negative pressure to the plurality of wound dressings, the plurality of fluid flow paths comprising: a first fluid flow path configured to fluidically connect a first wound dressing to the negative pressure source, the first wound dressing with a first fluid retention capacity; and a second fluid flow path configured to fluidically connect a second wound dressing to the negative pressure source, the second wound dressing with a second fluid retention capacity; a first fluid flow path configured to fluidically connect a first wound dressing to the negative pressure source, the first wound dressing with a first fluid retention capacity; and a second fluid flow path configured to fluidically connect a second wound dressing to the negative pressure source, the second wound dressing with a second fluid retention capacity; at least one pressure sensor configured to measure pressure associated with the plurality of fluid flow paths; and a controller configured to operate the negative pressure source, the controller further configured to: receive a plurality of pressure measurements from the at least one pressure sensor; determine from at least some of the plurality of pressure measurements first and second fluid retention capacities of the first and second wound dressings; determine a blockage threshold based at least in part on the determined first and second fluid retention capacities; detect presence of a blockage in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the blockage threshold; and provide an indication of the blockage in response to determining that the blockage threshold is satisfied. receive a plurality of pressure measurements from the at least one pressure sensor; determine from at least some of the plurality of pressure measurements first and second fluid retention capacities of the first and second wound dressings; determine a blockage threshold based at least in part on the determined first and second fluid retention capacities; detect presence of a blockage in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the blockage threshold; and provide an indication of the blockage in response to determining that the blockage threshold is satisfied.