| Image = | Caption = | DiseasesDB = 26877 | ICD10 = , | ICD9 = , , , | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = med | eMedicineTopic = 2698 | MeshID = D007319 | }} Insomnia is a sleeping disorder characterized by persistent difficulty falling asleep or staying asleep despite the opportunity. It is typically followed by functional impairment while awake. Insomniacs have been known to complain about being unable to close their eyes or "rest their mind" for more than a few minutes at a time. Both organic and non-organic insomnia constitute a sleep disorder. According to the U.S. Department of Health and Human Services, approximately 60 million Americans suffer from insomnia each year.