An impulse is a wish or urge, particularly a sudden one. It can be considered as a normal and fundamental part of human thought processes, but also one that can become problematic, as in a condition like obsessive-compulsive disorder,[unreliable medical source?] borderline personality disorder, attention deficit hyperactivity disorder, or in fetal alcohol spectrum disorders.
The ability to control impulses, or more specifically control the desire to act on them, is an important factor in personality and socialization. Deferred gratification, also known as impulse control is an example of this, concerning impulses primarily relating to things that a person wants or desires. Delayed gratification comes when one avoids acting on initial impulses. Delayed gratification has been studied in relation to childhood obesity. Resisting the urge to act on impulses is important to teach children, because it teaches the value of delayed gratification. 
Many psychological problems are characterized by a loss of control or a lack of control in specific situations. Usually, this lack of control is part of a pattern of behavior that also involves other maladaptive thoughts and actions, such as substance abuse problems or sexual disorders like the paraphilias (e.g. pedophilia and exhibitionism). When loss of control is only a component of a disorder, it usually does not have to be a part of the behavior pattern, and other symptoms must also be present for the diagnosis to be made. (Franklin[unreliable medical source?])
- "Acting on Impulse". Psychology Today. Retrieved 20 February 2016.
- Caleza, Carolina; Yañez-Vico, Rosa M.; Mendoza, Asunción; Iglesias-Linares, Alejandro (2016-02-01). "Childhood Obesity and Delayed Gratification Behavior: A Systematic Review of Experimental Studies". The Journal of Pediatrics. 169: 201–207.e1. doi:10.1016/j.jpeds.2015.10.008. ISSN 0022-3476.
- Psychological Impulse Control Disorders