Understanding the Different Types of Sleep Apnea

Experts estimate that some 30 million people in the United States — or just over one in four adults (26%) between the ages of 30 and 70 — have some form of sleep apnea. Of those, only about six million have been officially diagnosed with sleep-disordered breathing. 

At Fivestar Pulmonary Associates in Allen, McKinney, and Plano, Texas, we’re committed to helping patients understand this common — and exceedingly underdiagnosed — condition, including why treatment is so important. 

Read on as our seasoned team of board-certified pulmonologists discusses the three types of sleep apnea and how they’re managed. 

A short tutorial on sleep apnea

Sleep apnea is a breathing-related sleep disorder that triggers recurrent respiratory pauses as you sleep. Each time your brain senses low blood oxygen levels, it sends signals to stimulate respiration through a partial arousal and prevents healthy, restful sleep in the process. 

Whether these spontaneous respiratory pauses last for a few short seconds or longer than a minute, they can happen dozens of times in a single hour. Sleep apnea severity is determined by how many respiratory pause/partial awakening events it causes:

• Mild sleep apnea causes 5-14 events per hour
• Moderate sleep apnea causes 15-29 events per hour
• Severe sleep apnea causes 30 or more events per hour

To put these numbers in perspective, mild sleep apnea causes 40-112 breathing pause/partial awakening events over eight hours, moderate sleep apnea causes 120-139 events in an average night’s sleep, and severe sleep apnea triggers at least 240 events in eight hours. 

Each partial awakening disrupts your sleep cycle without waking you fully, which helps explain why people with undiagnosed sleep apnea don’t understand why they always feel exhausted.

Three main forms of sleep apnea

Although all cases of sleep apnea cause breathing pause/partial awakening events, the three forms of the condition are differentiated by how and why they happen. Let’s take a closer look at the three types of sleep apnea:

Obstructive sleep apnea (OSA)

OSA is the most frequently diagnosed form of sleep apnea. It occurs when the muscles that support the soft tissues in your throat temporarily relax, allowing your tongue and soft palate to collapse into your airway and obstruct respiration. You try to breathe, but you can’t. 

Although anyone can develop OSA, it’s a common complication of obesity. Most (though not all) people with OSA are overweight. In such cases, weight loss often improves the condition.

Central sleep apnea (CSA) 

A less common form of sleep apnea, CSA, begins with a problem in your brain. Your brain is the command-and-control center that manages every breath you take. CSA occurs when your brain doesn’t send signals to keep your airway muscles working, causing your respiration to pause or become shallow. Basically, your body stops trying to breathe. 

CSA can happen for many reasons, ranging from heart failure and altitude-induced low blood oxygen levels to nervous system conditions or damage (especially to your brain stem). CSA can also emerge at the start of treatment for OSA, as a temporary side effect of continuous positive airway pressure (CPAP) therapy. 

Mixed/complex sleep apnea 

When sleep apnea causes both obstructive and central breathing pause/partial awakening events, it’s called mixed sleep apnea or complex sleep apnea syndrome. 

Common sleep apnea symptoms

Sleep apnea symptoms fall into two general categories:

Nighttime effects

Most people with undiagnosed sleep apnea are completely unaware of its nighttime effects, or the abnormal breathing patterns it causes. Often, it’s a sleep partner who points out the loud, chronic snoring that can happen with OSA, or the breathing pauses, respiration rate changes, or gasping or choking for air that can occur with any form of the condition. 

Other nighttime symptoms include restless sleep with periods of wakefulness, an increased need to get up from the bed and urinate, and sudden shortness of breath or chest pains. 

Daytime effects 

Partial awakenings and a reduced quality of sleep typically give rise to daytime symptoms like excessive sleepiness or unexplained exhaustion, irritability, difficulty focusing, and frustration, a dry mouth upon waking, and morning headaches. 

The effects of sleep apnea don’t end with these symptoms, however; left untreated, sleep apnea and its breathing pause/partial awakening events can be very hard on your health — increasing your risk of many serious complications, ranging from hypertension and heart damage to heart arrhythmias and sudden death. 

Think you may have sleep apnea?

While sleep apnea affects people of all ages (including children), certain risk factors, including obesity, older age, family history, male gender, alcohol use, and smoking make it more likely. 

Luckily, sleep apnea is highly treatable, and it all starts with an expert evaluation, an overnight sleep study, and an accurate diagnosis. If you’re concerned about sleep apnea, we can help. Call or click online to schedule an appointment at your nearest Fivestar Pulmonary Associates office today.

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