High Serotonin

• Serotonin syndrome is a very serious effect of high levels of serotonin. Serotonin syndrome is often caused when a person combines prescription drugs that together substantially raise the body's level of serotonin. High levels of serotonin levels can cause a variety of side effects, including agitation or restlessness, diarrhea, fast heartbeat, hallucinations, nausea, loss of coordination, fever and vomiting.
  
  

Low Serotonin

• Low levels of serotonin can be just as dangerous as high levels. Serotonin is a neurotransmitter, which means that it transmits signals to other nerves and, therefore, facilitates overall nerve function. If the body is not producing enough serotonin, other chemical imbalances may result. Particularly, mood disorders result from decreased or abnormally low levels of serotonin. Persons with low levels of serotonin may experience weight gain or loss, mild or severe depression, anxiety and/or insomnia. If low serotonin levels are not treated, persons may also experience severe personality changes and suicidal thoughts or behaviors.
  
  

High Norepinephrine

• Norepinephrine, sometimes referred to as noradrenaline, is an excitatory neurotransmitter. It is produced by the adrenal medulla when the body experiences excitement. Norepinephrine, like adrenaline, is strongly linked to physical responses and reactions. Excessive levels of norepinephrine can lead to hyperactivity, since high levels enable the body to produce superfluous amounts of adrenaline and other stimulating chemicals. High levels of the chemical can also cause high blood pressure, rapid heartbeat, anxiety and stress.
  
  

Low Norepinephrine

• Since norepinephrine is responsible for boosting or stimulating the nerves and inciting activity in the body, low levels of norepinephrine can lead to lack of energy, inability to focus and decreased motivation to perform ordinary tasks. Often, persons diagnosed with Attention Deficit Hyperactive Disorder have lower-than-normal levels of the chemical. Abnormally low levels of norepinephrine can also result in loss of alertness, poor memory and depression.