diff --git a/init/libs.xml b/init/libs.xml
index 98aa92ca..1adadb2e 100644
--- a/init/libs.xml
+++ b/init/libs.xml
@@ -6,4 +6,5 @@
   <Include file="..\libs\librange.lua"/>
   <Include file="..\libs\libunitscan.lua"/>
   <Include file="..\libs\libtooltip.lua"/>
+  <Include file="..\libs\libhealth.lua"/>
 </Ui>
diff --git a/libs/libhealth.lua b/libs/libhealth.lua
new file mode 100644
index 00000000..a806e279
--- /dev/null
+++ b/libs/libhealth.lua
@@ -0,0 +1,62 @@
+-- load pfUI environment
+setfenv(1, pfUI:GetEnvironment())
+
+local mobdb
+local target, dmg, perc, diff = nil, 0, 0, 0, 0
+local libhealth = CreateFrame("Frame")
+libhealth:RegisterEvent("UNIT_HEALTH")
+libhealth:RegisterEvent("UNIT_COMBAT")
+libhealth:RegisterEvent("PLAYER_TARGET_CHANGED")
+libhealth:RegisterEvent("PLAYER_ENTERING_WORLD")
+libhealth:SetScript("OnEvent", function()
+  if event == "PLAYER_ENTERING_WORLD" then
+    pfUI_cache["libhealth"] = pfUI_cache["libhealth"] or {}
+    mobdb = pfUI_cache["libhealth"]
+  elseif event == "PLAYER_TARGET_CHANGED" then
+    dmg, perc = 0, _G.UnitHealth("target")
+    if UnitName("target") and UnitLevel("target") and _G.UnitHealthMax("target") == 100 then
+      target = string.format("%s:%d",UnitName("target"), UnitLevel("target"))
+    else
+      target = nil
+    end
+  elseif target and event == "UNIT_COMBAT" and arg1 == "target" then
+    dmg = dmg + arg4
+  elseif target and event == "UNIT_HEALTH" and arg1 == "target" then
+    diff = perc-_G.UnitHealth("target")
+    if dmg > 0 and diff > 0 then
+      mobdb[target] = mobdb[target] or {}
+      if not mobdb[target][2] or diff > mobdb[target][2] then
+        mobdb[target][1] = ceil(dmg / diff * 100)
+        mobdb[target][2] = diff
+        -- print(string.format("New Health of %s is %s", target, mobdb[target][1]))
+      end
+    end
+  end
+end)
+
+local unit, level, cur, max, dbstring
+local function GetHealthPairs(unitstr)
+  unit = UnitName(unitstr)
+  level = UnitLevel(unitstr)
+  cur = _G.UnitHealth(unitstr)
+  max = _G.UnitHealthMax(unitstr)
+
+  if unit and level and max == 100 then
+    dbstring = string.format("%s:%s", unit, level)
+    if mobdb[dbstring] and mobdb[dbstring][1] and mobdb[dbstring][2] > 5 then
+      return ceil(mobdb[dbstring][1]/100*cur), mobdb[dbstring][1]
+    end
+  end
+
+  return nil
+end
+
+pfUI.api.UnitHealth = function(unitstr)
+  cur, max = GetHealthPairs(unitstr)
+  return cur or _G.UnitHealth(unitstr)
+end
+
+pfUI.api.UnitHealthMax = function(unitstr)
+  cur, max = GetHealthPairs(unitstr)
+  return max or _G.UnitHealthMax(unitstr)
+end