Which of the following is NOT a physical withdrawal symptom?

Insomnia is not typically classified as a physical withdrawal symptom. Instead, it is more closely associated with psychological or emotional responses to withdrawal, as it reflects disruptions in sleep patterns often linked to anxiety or stress. Physical withdrawal symptoms usually involve observable or measurable physiological changes in the body.

Nausea, palpitations, and sweating are all well-documented physical symptoms that can arise during withdrawal from substances. Nausea is a common gastrointestinal reaction; palpitations relate to changes in heart rate and cardiovascular response; and sweating reflects abnormalities in the autonomic nervous system. Each of these symptoms can be directly linked to the physical stress that withdrawal places on the body, whereas insomnia primarily manifests as a disturbance in sleep without a direct physiological marker.