Hey as Nortriptyline is a tricyclic antidepressant. It affects chemicals in the brain that may become unbalanced.

Side effects
Heart disease, or a history of heart attack, stroke, or seizures;
A family history of sudden death related to a heart rhythm disorder;
Bipolar disorder (manic-depression);
Schizophrenia or other mental illness;
Liver disease;
A thyroid disorder;
Diabetes (nortriptyline may raise or lower blood sugar);
Narrow-angle glaucoma; or
Problems with urination.

Uses
This medication is used to treat mental/mood problems such as depression.
It may help improve mood and feelings of well-being, relieve anxiety and tension, and increase your energy level.
This medication belongs to a class of medications called tricyclic antidepressants.
It works by affecting the balance of certain natural chemicals (neurotransmitters) in the brain.

Other uses:
This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional.
Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.