Final answer:
Insomnia refers to the inability to obtain sufficient sleep, leading to a sleep debt with consequences such as reduced alertness and health issues.
Step-by-step explanation:
The failure to get enough sleep at night in order to feel rested the next day is known as insomnia. Accumulating a sleep debt can lead to serious consequences such as diminished mental alertness, cognitive function, and even adverse health effects like obesity and increased stress hormones.
Most adults require 7-9 hours of sleep each night, and failure to achieve this can result in symptoms including irritability and cognitive impairments. Particularly for individuals who drive, the risks are amplified, as sleep deprivation can impair reflexes and attention akin to the effects of alcohol intoxication. Thus, sleep debt is problematic because it augments the potential for accidents and decreases overall productivity and health.