It may seem straight forward, but you would be surprised how hard some of these signs are to spot: 

• An abundance of random sticks and branches on the ground. Although it is normal for some to be shaken loose seasonally, the tree dropping is also a sign that it is not healthy. 

• The bark is peeling or falling off. Although many think this is a sign of temperature change, this is a definite red flag. You may also notice the bark is cracking.

• Leaf or pine needle shortage. If your trees leaves are sparse or appear brown in colour, this may be a sign it may be in ened of some care.

• Visible rot or fungus. This may speak for itself, but disease can look different from tree to tree and is often hard to spot. If you see what appear to be small black dots creeping up the trunk, for instance, this may be a sign of rot. 

• An increase in pests and bugs. Insects and  pests feed on rot and can be a sign that the inside of the tree could be diseased. 
• The tree is starting to lean. Even a gradual lean can be a sign the tree is slowly dying.