I've not use the wrist unit but did have a cuff type that pumped up. I found the unit to be off quite a bit and returned it. Try to get a bp reading at a doc's office and compare the result to what ever unit you chose. BTW outside influences, job, stress, can effect readings. Try to take the reading consistently at the same time of day. Readings early morn. can be lower then later in the day. Try to take reading three times a week and track over a period of time and you may find an average range of your bp