Obstructive sleep apnea
Patients with obstructive sleep apnea stop and start breathing several times while asleep. This may occur several hundred times a night, with each occurrence lasting several seconds, causing heavy snoring, morning headache, sore throat or daytime drowsiness. If not properly treated, obstructive sleep apnea may result in irregular heartbeat, high blood pressure, heart failure, lung disease and impotence.
Insomnia is the inability to fall asleep. It may be caused by psychological factors, such as depression or stress, sleep apnea syndrome, muscle twitches during sleep, or physical pain. Environmental factors such as lifestyle and personal crisis may also result in insomnia.
Periodic leg movement syndrome
This condition involves leg muscle twitches that usually occur every 20 to 40 seconds during sleep. It leaves the patient feeling restless during the night or excessively tired and sleepy during the day, and can often lead to insomnia.
A person with narcolepsy falls asleep involuntarily at different times throughout the day. He or she may fall asleep while driving, eating or talking. A narcoleptic may lose muscle control during an emotional experience such as crying or laughing. Narcolepsy can cause extreme frustration for the sufferer, and can lead to life-threatening situations.