The first signs of sleep deprivation are usually increased yawning and a feeling of fatigue. This is your body's initial response to a lack of sleep.
As sleep deprivation continues, you might experience mood changes such as irritability, frustration, and mood swings.
Difficulty concentrating, memory problems, and a decrease in cognitive abilities become more noticeable.
Clumsiness and loss of coordination occur. Sleep deprivation disrupts motor abilities and reaction times due to central nervous system effects.
In more extreme cases of prolonged sleep deprivation, hallucinations and delusions (strong beliefs in things that are clearly not true) can occur.
These are brief sleep bouts when awake. Microsleeps, a sign of acute sleep deprivation, are dangerous, especially when driving.
Long-term sleep deprivation can cause immune system weakness, high blood pressure, diabetes, and heart disease.
In rare and extreme cases, chronic sleep deprivation might contribute to the development of fatal sleep disorders like fatal familial insomnia, a rare genetic condition.