How to make damage script only function when character is damaged?

I made a script that launches a player into the air when they get damaged. The problem is that it happens when the player is healed too. I have tried things like "if humanoid.Health < Health" but they all didn't work. It'd be great if someone helped me. The script is inserted inside the character model.

local ReplicatedStorage = game:GetService("ReplicatedStorage")
p = ReplicatedStorage:FindFirstChild("YellowPoof")
local tweeninfo = TweenInfo.new(0.85)
local ts = game:GetService("TweenService")
local goal = {}
goal.Size = Vector3.new(11, 11, 11)
goal.Transparency = 1
db = true

function onHurt()
	if db == true then
		db = false
		local humanoid = script.Parent.Humanoid
		local p2 = p:Clone()
		local tween = ts:Create(p2, tweeninfo, goal)
		p2.Parent = workspace
		p2.Position = humanoid.Parent.HumanoidRootPart.Position
		tween:Play()
		if humanoid.RigType == Enum.HumanoidRigType.R15 then
			local animation = humanoid:LoadAnimation(script.Animation)
			animation:Play()
		elseif humanoid.RigType == Enum.HumanoidRigType.R6 then
			local animation = humanoid:LoadAnimation(script.Animation2)
			animation:Play()
		end
		humanoid.Jump = true
		humanoid.WalkSpeed = 10
		wait(1.85)
		humanoid.WalkSpeed = 19.5
		p2:Destroy()
		db = true
end
end
script.Parent.Humanoid.HealthChanged:Connect(onHurt)

Well, for a damage script: EXAMPLE

local LavaBox = script.Parent
local DamageAmount = 10 -- you can change that

local function DealDamage(part)
	local hum = part.Parent:FindFirstChild("Humanoid)
	if hum then
		hum.Health - DamageAmount
	end
end
LavaBox.Touched:Connect(DealDamage)

and for fling, try this

Player.pos = (0, 5000, 0) -- can be changed