Which of the following conditions may cause constricted pupils?

Constricted pupils, also known as miosis, are often caused by specific factors related to bodily functions and the effects of various substances. In the context of drug overdose, especially with opioids, miosis is a well-documented symptom. Opioids, such as morphine, heroin, and prescription pain medications, can activate the parasympathetic nervous system, leading to a decrease in pupil size.

When a person overdoses on opioids, the central nervous system is significantly depressed, which can result in other critical symptoms, including respiratory depression, unconsciousness, and decreased heart rate. The presence of pinpoint pupils is one of the classic signs that medical professionals look for in cases of opioid overdose. Recognizing this symptom can be crucial for EMTs as it helps guide their assessment and treatment, including the administration of naloxone (Narcan) to reverse the effects of the overdose.

Other conditions, such as stimulant drug influence, head injury, and exposure to smoke, typically cause the opposite effect by leading to dilated pupils. Stimulant drugs, for instance, increase sympathetic nervous system activity, while head injuries and exposure to smoke can also affect the nervous system in a way that leads to pupil dilation rather than constriction. Therefore,