Which of the following is a common symptom of insomnia?

• A. Excessive daytime sleepiness
• B. Vivid dreams
• C. Sleepwalking
• D. Difficulty falling asleep

Answer: (D)

Verified step by step guidance

1. Understand the definition of insomnia: it is a sleep disorder characterized primarily by difficulty falling asleep, staying asleep, or getting restful sleep.
2. Review common symptoms associated with insomnia, focusing on those directly related to the initiation and maintenance of sleep.
3. Compare the options given: Excessive daytime sleepiness can be a consequence of insomnia but is not the primary symptom; vivid dreams and sleepwalking are generally linked to other sleep disorders.
4. Identify that 'Difficulty falling asleep' directly matches the core symptom of insomnia, making it the most accurate choice.
5. Conclude that recognizing the hallmark symptom of insomnia helps differentiate it from other sleep-related issues.