When emotions are triggered chemically, many things can happen. Such as, the chemical serotonin keeps almost everything balanced and when you don't have enough, it can lead to suicide. Dopamine triggers your adrenaline hormone, and norepinephrine makes you feel simple emotions. Emotional eating can affect your body in many ways, positive and negative. Fight or flight response is actually a series of chemical reactions.
Chemical Emotions

Emotion:

    Emotion - n: The effective aspect of consciousness; a state of feeling; a conscious mental reaction (anger or fear) subjectively experienced as a strong feeling usually directed toward a specific object and typically accompanied by psychological and behavioral changes in the body.

Norepinephrine

    norepinephrine - n: holamine C 8 H 11 NO 3 that is the chemical means oftransmission across synapses in postganglionic neurons of 
thesympathetic nervous system and in some parts of the centralnervous system, is a vasopressor
hormone of the adrenal medulla,and is a precursor of epinephrine in it's major biosynthetic pathway

Dopamine

    dopamine - n: a monoamine C 8 H 11 NO 2 that is a decarboxylated form of dopa and occurs especially as a neurotransmitter in the brain andas an intermediate in the biosynthesis of epinephrine

Serotonin

     serotinin - n: a phenolic amine neurotransmitter C 10 H 12 N 2 O that is a powerful 
vasoconstrictor and is found especially in the brain, bloodserum, and gastric mucous membrane of mammals
Chemical emotions tells you about how emotions are connected to chemistry, and many other topics, like how they affect our daily lives.