Sleep problems, particularly sleep deprivation and fragmentations, are common hazards in modern lifestyles and maybe an unavoidable occupational drawback. Different metabolic or hereditary causes may induce sleep problems. Cognitive functions and the closely related metacognition, which depends significantly on decision making, are essential for learning and problem-solving. When impaired for any reason, the quality of life deteriorates, and the person may become dependent on others in severe cases of dysfunction. Sleep and cognition/metacognition are related, and an insult to one function may lead to the other domain's collapse. The present review highlights the significant causes and conditions of sleep problems, cognitive and metacognitive dysfunctions, the possible mechanisms, interactions, and the potential tools or agents that may improve them.