Secondary insomnia means that all the difficulties that you face to fall asleep and stay asleep all night is maybe because of a health disorder or problems like depression, cancer, asthma, arthritis, and heartburn. The cause of secondary insomnia can be medication or a recreational substance like alcohol and tobacco smoking. The sleeplessness can be due to some pain that you are experiencing, and it is not letting your mind go to have a good sleep. Some medications also have certain chemicals in them that interfere with the sleep hormones in the body and cause an inability to sleep. The substance use like drinking alcohol or using drugs can also deprive your body to go in the peaceful state of getting asleep. Secondary insomnia is also known as comorbid insomnia because it can be due to a medical illness, or it might be due to a separate psychiatric disorder. If a person has the diagnosis of secondary insomnia, this person may be having all the bad nights due to some different illness, which can worsen the condition even more.