Lesson 3 explained that insomnia is often maintained by habits that began as ways of coping with poor sleep. This lesson identifies the most common ones and explains how they can affect your nights.

You do not need to change anything yet. Unit 2 will guide you through that process. For now, simply notice which of these habits are part of your routine.

Napping. Sleeping during the day reduces some of the sleep drive that has built while you were awake. As a result, you may have less pressure to sleep when night arrives.

A nap does not create additional sleep. It moves part of your sleep into the daytime, which can make falling asleep or staying asleep more difficult that night.

The main recommendation is to avoid daytime naps. If you genuinely cannot avoid one, keep it under an hour and finish it before 3 p.m.

Staying in bed longer and going to bed earlier. Both habits come from the same understandable goal: spending more time in bed to recover lost sleep.

However, more time in bed does not necessarily produce more sleep. It can reduce the proportion of that time you spend asleep and create more opportunities to lie awake. This is one of the most common habits that maintains insomnia, and changing it is a major focus of Unit 2.

Alcohol. Alcohol can make you feel drowsy and help you fall asleep more quickly. Later in the night, however, it can make sleep lighter, more fragmented and less refreshing.

This can help explain why some people fall asleep easily after drinking but wake around 3 a.m. As the body processes the alcohol, sleep may become more disrupted. You may gain an easier first part of the night but experience more awakenings later.

If you regularly use alcohol to help yourself fall asleep, it may be contributing to difficulties staying asleep.

Caffeine. Caffeine is a stimulant and can remain in your system for several hours. Consuming it later in the day may make it harder to fall asleep or sleep well at night.

This program recommends limiting caffeine to the equivalent of no more than three cups of coffee per day and avoiding it in the late afternoon and evening.

This does not mean that you must completely remove caffeine. The aim is to set a reasonable limit and a clear cut-off time.

Exercise is a helpful habit. Regular, moderate exercise can support deeper and better-quality sleep. The main caution concerns intense exercise close to bedtime, which may leave you too alert to fall asleep quickly.

Exercise in the late afternoon or early evening may work well for many people, but the most useful timing is one that fits your body and routine.

These habits are worth reviewing, but they are not the complete treatment. Advice about naps, caffeine, alcohol and exercise is not recommended as a standalone treatment for insomnia.

If adjusting these habits were enough to resolve persistent sleep difficulties, it might already have done so. The main part of the program begins in Unit 2. Think of this lesson as preparing the ground for that work.