Obstructive Sleep Apnea
Obstructive sleep apnea occurs when your airways shut down while sleeping at night, causing you to stop breathing and wake up. This disorder is very common, and it affects men and women of all different ages. Additionally, it can lead to strokes and high blood pressure, and symptoms can include snoring, restless sleep, waking up suddenly from sleep, cessation of breathing, restless sleep, daytime tiredness, forgetfulness, and irritability. While no one actually knows the exact cause of sleep apnea, it could be a result of many different factors, such as having large tonsils, blockages in the nasal airways, or narrowed airways.

Insomnia
Insomnia is the inability to fall asleep or stay asleep. Some causes could be emotional stress, health reasons, or sleep apnea.

Narcolepsy
Narcolepsy is falling asleep while you're active or doing things. It involves the sudden onset of extreme sleepiness that you can't control, such as falling asleep driving, at work, or while talking to people. With narcolepsy, the symptoms are more drastic when you fall asleep during normal activities, and the amount of times it happens varies, as well.