Insomnia is a common sleep disorder that makes it difficult to fall asleep, stay asleep, or get restful sleep throughout the night. People with insomnia often experience fatigue, poor concentration, and irritability during the day. Causes can include stress, lifestyle habits, medical conditions, or changes in routine. Treatment may involve improving sleep hygiene, cognitive behavioral therapy, relaxation techniques, or in some cases, prescribed medications. With proper support, many individuals are able to restore healthy sleep patterns.