what is sleeping apnea and what are the symptoms?

oliver_a2002 says:

Sleep Apnea is periodic involuntary interruptions in your breathing while sleeping.

gangadharan_nair says:

Central sleep apnea is a heterogeneous group of conditions characterized by changes in ventilatory drive without airway obstruction; most of these conditions cause asymptomatic changes in breathing pattern during sleep.
Obstructive sleep apnea consists of episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of apnea > 10 sec). Symptoms include restlessness, snoring, recurrent awakening, morning headache, and excessive daytime sleepiness. Diagnosis is based on sleep history, and polysomnography. Treatment is with nasal continuous positive airway pressure, oral appliances, and, in refractory cases, surgery. Prognosis is good with treatment. Most cases remain undiagnosed and untreated and are often associated with hypertension, heart failure, and injury or death from motor vehicle crashes and other accidents resulting from hypersomnolence.
Obstructive sleep apnea in children is episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation. Symptoms include snoring and sometimes restless sleep, nocturnal sweating, and morning headache. Complications may include growth disturbance, cor pulmonale, pulmonary hypertension, and learning or behavioral disturbances. Diagnosis is by polysomnography. Treatment is usually adenotonsillectomy.