What is insomnia? Insomnia is the inability to sleep either regularly such as naps or at night when necessary. Where does insomnia derive from? The honest answer is reasons for insomnia can vary. For some people they may suffer from insomnia due to daily stressors such as their job, tasks, and amount of responsibilities they may have. For others it could be due to a chemical imbalance such as anxiety, depression, or even deeply rooted stress.