What is a common side effect of narcotic use?

Constipation is a well-documented side effect of narcotic use due to the way these medications interact with the body's gastrointestinal system. Narcotics, or opioids, work by binding to specific receptors in the brain and spinal cord, which not only reduces the perception of pain but also slows down the movement of the intestines. This slowing effect can lead to decreased bowel motility and result in constipation, making it a pervasive issue for patients who are prescribed these medications.

While the other options may have some connection to narcotic use under certain circumstances, they are not as commonly associated as constipation. Diarrhea can occur due to other underlying issues or as a result of the body adjusting to the medication, insomnia can be a side effect of withdrawal rather than of continued use, and hypertension is not typically linked directly to narcotic use. Therefore, constipation stands out as the most significant and common side effect among the choices given.