A nurse is discussing the stages of the sleep cycle with a client. The nurse should include that the immune system is strengthened and tissues and bones are repaired during which of the following stages of the sleep cycle?

A. Shift work disrupts the normal circadian rhythm, leading to irregular sleep patterns, altered eating habits, and metabolic changes. These disruptions increase the risk for insulin resistance and impaired glucose metabolism, which can contribute to the development of type 2 diabetes mellitus. Multiple studies have shown a higher prevalence of diabetes in individuals who perform night shifts or rotating shifts compared to those with consistent daytime schedules.

B. Central sleep apnea is caused by a failure of the brain to send appropriate signals to the respiratory muscles, often associated with heart failure, stroke, or opioid use. It is not specifically linked to shift work or circadian rhythm disruption.

C. While shift workers may experience excessive daytime sleepiness due to sleep deprivation or circadian misalignment, hypersomnia is a sleep disorder characterized by excessive sleep despite adequate sleep opportunities and is not a direct consequence of shift work. Shift work primarily causes circadian rhythm–related sleep disturbances rather than intrinsic hypersomnia.

D. RLS is a neurological disorder characterized by uncomfortable sensations in the legs with an urge to move them, often worse at night. It is not caused by shift work, although sleep disruption may exacerbate symptoms in individuals with preexisting RLS.

A. Hyperactivity is not a common adverse effect of OTC sleep aids. These medications, which often contain antihistamines such as diphenhydramine, are generally sedating rather than stimulating, and they are more likely to cause drowsiness, grogginess, or confusion, especially in older adults.

B. Diarrhea is not typically associated with OTC sleep aids. While gastrointestinal upset can occasionally occur with any medication, diarrhea is not a characteristic or common adverse effect of these sedating agents.

C. Excessive salivation is not commonly seen with OTC sleep aids. In fact, antihistamine-containing sleep aids more often cause dry mouth rather than increased salivation due to their anticholinergic effects.

D. Urinary retention is a potential adverse effect of OTC sleep aids that contain antihistamines. Anticholinergic properties of these medications can reduce bladder detrusor muscle activity, making it difficult for clients to empty the bladder. This effect is particularly concerning in older adults or clients with preexisting urinary issues such as benign prostatic hyperplasia.