As you may know, the memory cells in solid state devices experience wear during each write operations and each cells tolerate only a limited number of program/erase (overwrite) passes.

The "wear-leveling" feature of the SSD tries to hide/minimise this effect but generally it can't be avoided and the SSD device usually calculates the overall health of the memory cells. If there are no further problems found, Hard Disk Sentinel reads these values which determine the complete health of the solid state device.

This is what you can see in the text description area (for example):

   The status of the solid state disk is PERFECT. Problematic or weak sectors were not found.
   The health is determined by SSD specific S.M.A.R.T. attribute(s):  #231 SSD Life Left

What does it mean? There are no problems found (so the SSD works without problems, tests will show no errors) but the 231 SSD Life Left attribute determines the overall health of the device. If you want, you may check how that attribute changes with time on the S.M.A.R.T.  page. Please note that the attribute number and name may be different, related to the current SSD manufacturer/model.

This is completely independent from software, OS, restart and so: as the amount of written data increases, the health will slowly and surely decrease. This is completely normal and not bad, as this way we can prepare for planned replacement when the health will be really low (eg. 25% or lower). To slow down the degradation, if possible, please try to minimise the amount of data written to the SSD.

This is described in the Help too, online at
Health calculation
(see the bottom of the page for SSD health information).

Also the page
SSD health decrease by wearout
describes the situation with more details.