1. Will getting 1 hour less of sleep per night affect daytime functioning? Yes, it will compromise a person’s thinking and responding abilities, in addition to impacting cardiovascular health, energy balance and immune function.

2. Does the body adapt easily to different sleep schedules—for example, during travel across several time zones? No, it can take more than a week to adjust when traveling across several time zones. However, most people can easily reset their sleep pattern when experiencing a 1- to 2-hour time zone difference.

3. How long does it take to adjust when switching to a night-shift job? About 1 week.

4. What is the cause of excessive daytime sleepiness? In addition to self-imposed sleep deprivation, insomnia is a main cause of daytime sleepiness. Other causes include some sleep disorders, such as sleep-disordered breathing, restless leg syndrome and narcolepsy (a neurological disorder characterized by disabling sleepiness).

5. Can you make up for lost sleep during the week by sleeping more on the weekend? Not a good strategy, although many people take this approach. Sleeping later on weekends will affect your sleep-wake cycle and potentially make it harder for you to go to sleep on Sunday evening and to get up on Monday morning.

6. Are there differences in sleep disturbances between men and women? Yes, women of all ages report more sleeping problems than men.

7. What happens to sleep patterns as a person ages? Sleep efficiency and slow-wave sleep decrease with age (≥52 years). A person’s circadian rhythm (the body’s 24-hour cycle for biochemical and physiological processes) also alters, which may hinder sleep.

8. Will caffeine intake affect sleep? Caffeine (found in soft drinks, coffee, tea and chocolate) alters chemical reactions in the brain, causing those who consume it to feel more energetic and alert. It may delay sleep onset, reduce total sleep time and decrease the overall quality of a person’s sleep. However, such alterations depend on the time of day the caffeine is consumed, the amount consumed and an individual’s sensitivity to caffeine.

9. Do infants and teenagers need more sleep than others in each 24-hour cycle? Yes, infants need 14–18 hours of sleep per cycle, and teenage boys and girls need about 9 hours of sleep per cycle.

10. Are short naps beneficial after a night of sleep loss? Yes, a short nap (<15 minutes) in the mid-afternoon after an evening of restricted sleep will result in fewer major and minor driving accidents. This has been demonstrated in car-driving simulator studies.

by Len Kravitz, PhD

Sources: Alhola & Polo-Kantola 2007; WebMD 2010