Disclosed is a memory device which includes a memory core that includes a plurality of memory cells, and control logic that receives a first active command and a first row address from an external device and activates memory cells corresponding to the first row address from among the plurality of memory cells in response to the first active command. The control logic includes registers and counters. The control logic records the first row address in one of the registers, counts an activation count of the first row address by using a first counter of the counters, and counts a lifetime count of the first row address by using a second counter of the counters.