Why isn't script properly Checking Humanoid?

Purpose Of Script: Make the values true when Health is 50 and bellow , then make it false if above 50

Problem: It does not change the values, there are no errors in the output and the only things that are printed are-Checking-Good Hp-false-false, I have used a sword in my place and when it's health is clearly below 50 or even 0 It still says Good Hp, I do not know what's the problem, I have tried things like changing the variables to waitforchild,findfirstchild and regular format(script.parent.[NAME])

Script Location: Its located in the NPC there is a humanoid, and is named such, it is a regular script

Script

local humanoid = script.Parent:FindFirstChild('Humanoid')
local Health = humanoid.Health
local MaxHealth = humanoid.MaxHealth


function Check2()	
local Boss = script.Parent
local FieldDefense = script.Parent:WaitForChild('FieldDefense')
local Healing = script.Parent:WaitForChild('Healing')		
	
if Health > 50 then
print('Good Hp')
FieldDefense.Value = false	
Healing.Value = false
print(Healing.Value)
print(FieldDefense.Value)
end	
end

function Check()

local Boss = script.Parent
local FieldDefense = script.Parent:WaitForChild('FieldDefense')
local Healing = script.Parent:WaitForChild('Healing')
	
if Health <= 50 then	
print('Low Hp')
FieldDefense.Value = true
Healing.Value = true
print(Healing.Value)
print(FieldDefense.Value)
end
end

while wait(.1) do
print("Checking")
Check()	
Check2()
	
	
end

I recommend to REMOVE the health & MaxHealth

health = humanoid.Health

It's because if you do that, it won't work that way!

Here's a code that will work!

local humanoid = script.Parent:FindFirstChild('Humanoid')

function Check2()  
local Boss = script.Parent
local FieldDefense = script.Parent:WaitForChild('FieldDefense')
local Healing = script.Parent:WaitForChild('Healing')      
if humanoid.Health > 50 then
print('Good Hp')
FieldDefense.Value = false 
Healing.Value = false
print(Healing.Value)
print(FieldDefense.Value)
end
end
function Check()
local Boss = script.Parent
local FieldDefense = script.Parent:WaitForChild('FieldDefense')
local Healing = script.Parent:WaitForChild('Healing')
if humanoid.Health <= 50 then   
print('Low Hp')
FieldDefense.Value = true
Healing.Value = true
print(Healing.Value)
print(FieldDefense.Value)
end
end
while wait(.1) do
print("Checking")
Check()
Check2()
end

If it doesn't work, please PM me.