Common signs of tree stress are:

• Leaves are not the right color, usually lighter (iron deficiency).
• The limbs do not show new growth (dead limbs).
• The limbs are covered in bugs (spray pesticide or organic sprays).
• The leaves curl unnaturally or never fully open (bug infestation- spray).
• Leaves randomly turn brown and fall off (usually watering issue- either too much or not enough or lack of nutrients in the soil).
• Leaves never grow (possibly dead limbs or plant).
• Spots on the leaves (fungus- spray fungicide or blight- spray coppertone).
• Spots on the limbs (blight- spray coppertone).