The damage particles currently only shows if it affects your Health whether it be damage or healing. It won't show if it affects Absorption or the value will be slightly off.

For example... I have 20 Health and 8 Absorption and I take... say... 12 damage. The damage particle will show but will only show a 4 since that was affecting my health directly.

Now if I had 20 Absorption... somehow and I took 10 damage, no damage particle will appear since it didn't affect my health directly.