Sleep disordered breathing (SDB)

Sleep disordered breathing (SDB) describes a group of disorders characterized by:

1. Abnormal respiratory patterns (e.g. the presence of apneas or hypopneas); or
2. Insufficient ventilation during sleep.

An apnea is when a patient stops breathing for 10 seconds or more, and wakes up just enough to take a breath.

A hypopnea is when a patient doesn’t stop breathing, but the patient’s breathing becomes shallow (i.e., at least a 30% decrease in airflow) for 10 seconds or more, with an associated oxygen desaturation or arousal.

Either way, sleep disordered breathing disrupts the patient’s sleep pattern, night after night, which not only makes the patient tired and exhausted the next day, but may also put excessive strain on the patient’s nervous system and major organs.


Types of sleep disordered breathing (SDB)
There are three main types of sleep-disordered breathing as manifested in sleep apnea. Discovering the specific differences between them can help you recognize the different types of SDB in your patients.

1. Obstructive sleep apnea (OSA)

2. Central sleep apnea (CSA)

3. Mixed sleep apnea
Obstructive sleep apnea (OSA)

Obstructive sleep apnea (OSA) occurs when a patient’s upper airway closes (either partially or fully) but efforts to breathe continue.

The primary causes of upper airway obstruction are:

lack of muscle tone during sleep
excess tissue in the upper airway
the structure of the upper airway and jaw
OSA is the most common form of sleep apnea, affecting more than three in ten men and nearly one in five women.*
Central sleep apnea (CSA)

CSA occurs when the patient’s airway is open, but respiratory effort ceases due to a decrease in his or her ventilatory drive. It is a central nervous system disorder.

CSA can be caused by heart failure, or disease or injury involving the brain, such as:

brain tumor
viral brain infection
chronic respiratory disease
Patients with CSA don’t often snore, so the condition sometimes goes unnoticed.
Mixed sleep apnea

Mixed sleep apnea occurs when the patient shows signs of both OSA (where the airway is obstructed) and CSA (where no effort is made to breathe).


Common symptoms of sleep disorders

The symptoms of sleep disorders and sleep-disordered breathing (SDB)  are important to recognize in patients.

One of the most recognizable symptoms of sleep disorders is snoring, even though many patients ignore this sign or fail to recognize it as a symptom of a more serious condition.

Other symptoms of sleep-disordered breathing may include:

  • excessive daytime sleepiness (EDS)
  • poor concentration
  • morning headaches
  • depressed mood
  • night sweats
  • weight gain
  • fatigue
  • forgetfulness
  • sexual dysfunction
  • nocturia

If the patient presents with any of these symptoms, it’s important to talk to them about SDB and recommend a sleep test.

However, these symptoms of sleep disorders may not relate to sleep apnea, so it’s important that an accurate diagnosis is made.
Symptoms of sleep-disordered breathing in children

Sleep-disordered breathing also affects up to 3% of children, with common symptoms including:

  • habitual snoring (which affects about 3.2 – 12% of children)
  • noisy breathing/increased work of breathing
  • pauses in breathing with noisy resumption of breathing
  • chronic mouth breathing
  • behavioral problems, such as hyperactivity and aggressiveness
  • restless sleep

There are a number of risk factors that could also predispose children to having sleep-disordered breathing, including:

  • Adenotonsillar hypertrophy
  • Craniofacial malformation
  • Congenital syndromes (e.g. Down’s, Marfan’s, Pierre Robin Sequence, Achondroplasia)
  • Obesity

If symptoms of sleep-disordered breathing are observed in a child, it’s important to either refer the child to a pediatric sleep physician and/or recommend a sleep test to determine whether he or she has a breathing disorder.

Screening and diagnosis for sleep disordered breathing

If you suspect a patient may have sleep-disordered breathing, this three step screening process for SDB can get the patient on the path to getting diagnosed.

Can you recognize some of the common symptoms of SDB in the patient?

Ask the patient to complete a simple five-question sleep apnea symptom test as a quick screener.

Recommend the patient takes a sleep study to determine whether or not they have SDB, and if they do, to determine how severe it is.