Sleep apnea is a serious sleep disorder that occurs when a person’s breathing is interrupted during sleep. People with sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night.

There are two types of sleep apnea: obstructive and central. Obstructive sleep apnea (OSA) is the more common of the two. It is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses during sleep. In central sleep apnea, the airway is not blocked but the brain fails to signal the muscles to breathe due to instability in the respiratory control center.

It is estimated that more than 20 million Americans suffer from OSA, but as many as 80 to 90 percent go undiagnosed and untreated. Sleep apnea is considered to be a disease, and if left untreated, it can create serious health problems.

The condition known as OSA is created when tissues in the lower throat collapse at intervals during sleep, blocking the airway to the lungs and halting the normal breathing rhythm. Here’s how it usually happens:

  • On its way to the lungs, air passes through the nose, mouth, and throat (known as the upper airway)
  • Under normal conditions, muscles known as dilators work to keep the soft tissues of the throat from collapsing into the airway as a person breathes
  • If these muscles become too relaxed during sleep, the soft tissues of the mouth and throat will collapse backward and block the airway
  • Enlarged or excess soft tissues can increase the likelihood of blockage occurring
  • Blockage causes a temporary stoppage of breath, or apnea, and halts the supply of fresh oxygen to the body
  • The apnea causes blood oxygen levels to drop, and creates a buildup of carbon dioxide in the lungs
  • In a reflexive, subconscious reaction, stress hormones are released to momentarily rouse the body from sleep to resume breathing

Sometimes, an apnea suffer will be fully roused from sleep to gasp for air. But in most cases, they don’t fully wake after each pause in breath, and are often unaware of the stop-start breathing pattern that punctuates their sleep. This pattern not only interferes with deep, restful sleep, it also places significant stresses on the body, due to both the lower blood oxygen levels and the ongoing release of stress hormones with each partial waking.

If the airway is partially blocked, the condition is known as obstructive hypopnea. This results in continuous but slow and shallow breathing, and a reduction in oxygen supply to the body. Both apnea and hypopnea lead to poor sleep quality, and can cause or increase the risk of a wide range of health problems. Because sleep apnea often includes noisy and irregular snoring and gasping noises, the condition can also adversely affect the sleep quality of a patient’s bed partner. Spouses or partners may also suffer from sleeplessness and fatigue. In some cases, the snoring can even disrupt relationships. Diagnosis and treatment of sleep apnea in the patient can help eliminate these problems.