A nurse is caring for a client who reports that they use their smartphone at night while they are in bed. The nurse should identify that excessive smartphone use can increase the client's risk for which of the following?

A. This statement is incorrect because sleep enhances the formation of new neural pathways through a process called synaptic plasticity. During sleep, particularly during deep non-REM sleep, the brain strengthens neural connections formed during the day, which supports learning, memory consolidation, problem-solving, and cognitive performance. Lack of adequate sleep disrupts these processes, leading to decreased retention and impaired cognitive function.

B. During sleep, especially stage 3 non-REM (slow-wave) sleep, the glymphatic system becomes highly active. This system allows cerebrospinal fluid to circulate more freely through the brain, removing metabolic waste products such as beta-amyloid and other toxins that accumulate while awake. This waste clearance supports neuronal health, cognitive function, and protection against neurodegenerative diseases. Additionally, neuronal activity continues during sleep, allowing the brain to process memories, regulate emotions, and maintain overall neural communication.

C. The circadian rhythm is an internal biological clock located in the suprachiasmatic nucleus of the hypothalamus. It regulates the sleep-wake cycle, hormone secretion, body temperature, and other physiological processes. While external cues (zeitgebers) like light, temperature, and social activity can influence it, the rhythm itself is internally generated, not purely external. Misalignment of the circadian rhythm, as seen in shift work or jet lag, can disrupt sleep quality and overall health.

D. quality sleep requires progression through all sleep stages, including N1, N2, N3 (deep sleep), and REM sleep. Skipping any stage can impair restorative functions, memory consolidation, and overall physiological recovery.

A. This is a defining feature of hypersomnia. Clients experience excessive daytime sleepiness despite getting adequate or even prolonged sleep at night. The sleep is often non-restorative, meaning the client wakes still feeling tired, and additional sleep does not resolve the fatigue. This distinguishes hypersomnia from simple sleep deprivation.

B. While circadian rhythm disorders (like delayed sleep phase or shift work sleep disorder) can cause sleepiness, hypersomnia is not primarily caused by circadian rhythm disruption. It is a sleep disorder characterized by excessive sleepiness even with a normal sleep-wake schedule.

C. Hypersomnia actually impairs attention, concentration, and cognitive performance due to persistent sleepiness. Clients may experience difficulty focusing, memory lapses, and slowed mental processing, so a longer attention span is incorrect.

D. Lack of hypocretin (orexin) is primarily associated with narcolepsy type 1 (NT1), which includes cataplexy, not hypersomnia. Hypersomnia generally occurs without hypocretin deficiency.