Post-traumatic stress disorder (PTSD) is a psychological reaction to experiencing or witnessing a significantly stressful, traumatic or shocking event. Living through PTSD can be an overwhelming, frightening, isolating and debilitating experience. People with PTSD may be constantly watchful or jumpy. Their sleep is often disturbed and they may feel irritable and angry with themselves and others. Memory, concentration and decision-making are often affected.

Narcolepsy is the second leading cause of daytime sleepiness. It is a neurological disorder that can cause someone to fall asleep while engaging in any activity, including working, driving, or having a conversation.

Symptoms associated with Narcolepsy are Automatic behavior, Excessive daytime sleepiness, Hypnagogic hallucinations, Muscle weakness and loss of muscle control (cataplexy), Sleep paralysis and Uncontrolled sleep episodes.

Insomnia disorder is a long-term condition in which a person has trouble falling asleep, staying asleep through the night, or waking up too early in the morning, and the sleeping problem lasts at least 3 months. Insomnia disorder can last many years.

Hypersomnia, also known as hypersomnolence, is a condition involving excessive daytime sleepiness or prolonged nighttime sleep on a recurring basis. Adolescents and young adults are most likely to be affected by the condition.

It often causes affected individuals to take repeated naps throughout the day, which may disrupt other activities, such as work, study or social activities. These naps typically only provide temporary relief of symptoms and the desire to nap returns shortly afterward.

Bipolar disorder is characterized by extreme changes in mood, from mania (emotional highs) to depression (lows).

Symptoms of bipolar disorder may appear to be part of another illness such as substance abuse, poor school performance or trouble in the workplace, before being properly diagnosed.