How does alcohol affect sleep, and what is a common daytime consequence?

• A. Alcohol disrupts sleep architecture, leading to poor sleep quality, daytime sleepiness, and impaired concentration.
• B. Alcohol improves sleep quality and daytime alertness.
• C. Alcohol has no effect on sleep architecture.
• D. Alcohol only affects REM sleep but not daytime functioning.

Answer: (A)

Alcohol affects sleep by altering sleep architecture. It may help you fall asleep faster, but as the body processes the alcohol, sleep becomes more fragmented with more awakenings and lighter sleep. It tends to reduce REM sleep and slow-wave (deep) sleep, making sleep less restorative. The result is poorer sleep quality, even if you feel you slept quickly. Because the night is less restorative, you’re more likely to wake feeling tired or groggy, and during the day you’re prone to sleepiness, trouble focusing, and impaired concentration. This combination explains why the best answer links disrupted sleep stages with daytime tiredness and reduced alertness.