Which of the following side effects can occur from smoking cessation?

When someone stops smoking, they may experience a range of withdrawal symptoms as the body adjusts to the absence of nicotine. Insomnia is a common side effect during this transition, often occurring due to changes in brain chemistry and increased anxiety that can come with nicotine withdrawal. As the body works to recalibrate after long-term nicotine exposure, sleep disturbances, including difficulties falling asleep or staying asleep, can manifest.

In contrast, improved lung function, lower cholesterol levels, and increased energy are generally associated with the long-term benefits of smoking cessation rather than immediate side effects. These improvements reflect the positive physiological changes that occur as the body begins to heal from the damage caused by smoking. While these benefits take place over time, the short-term experience for many individuals includes withdrawal effects like insomnia. Thus, insomnia is correctly identified as a side effect of smoking cessation.