Three conditions; a variety of risk factors  

 There are three types of sleep apnea: obstructive sleep apnea (OSA), central sleep apnea (CSA), and mixed sleep apnea. While the symptoms of each type are similar, the underlying causes for these conditions are different. This article examines those causes.  

 Obstructive sleep apnea  

OSA is the most common type of sleep apnea. With this condition, your upper airway is blocked by the soft tissue that collapses when the muscles in your throat close too much as you sleep.¹ 

There are several risk factors that increase your chances of developing OSA:   

• Obesity. Being overweight or obese may significantly increase your risk because excess weight and fatty tissue can put pressure on your airway and prevent proper breathing.² According to research, weight gain of just 10% in individuals with mild OSA can mean the risk of progression of their OSA is six times greater.³ 

• Ageing. The older you get, the more at risk you are of developing OSA.² When ageing combines with obesity, the risk can be even more pronounced.  

• Biological sex. OSA is more prevalent in men, but women are still at risk, particularly if they are overweight or have gone through menopause.^4,5 

• Anatomy. A wide neck can indicate you have a narrow airway which can increase the likelihood of OSA. Also, the position of your neck, jaw, and tongue can impact your airways and contribute to the condition. People who have difficulty breathing through their nose could also be at risk of OSA as are adults and children who have enlarged tonsils or adenoids as this can restrict airflow.^2,12  

Other factors to consider  

• Alcohol and medication. Although not a risk factor, excess alcohol consumption can intensify the symptoms of OSA as it relaxes the muscles in your throat. Likewise, medications with sedative effects and tranquilizers can also make existing OSA worse.⁶ 

• Position during sleep. Sleeping on your back is not a risk factor, but this behaviour may exacerbate sleep apnea as it can cause your airway to collapse.¹³ 

Central sleep apnea  

Central sleep apnea (CSA) is much rarer than OSA. Unlike OSA, which is caused by an obstruction in the breathing area when the muscles in your throat relax during sleep, CSA occurs when the brain fires off the wrong signals to the muscles responsible for controlling your breathing.⁷  

The brain stem misreads carbon dioxide levels during sleep, which can lead to respiration that is shallower than normal and for short periods your breathing may stop altogether. It is common for people with CSA to find it difficult getting to sleep or staying asleep and you could find you awaken short of breath throughout the night. Daytime sleepiness is a common symptom of CSA. ^₈  

CSA is typically due to an underlying medical condition, usually one that has damaged the brain stem. Other risk factors include:  

• Ageing. Like OSA, getting older means you have a higher risk of CSA, especially once you have reached middle age. It is worth noting that obesity is not a risk factor for this type of sleep apnea.⁹  

• Biological sex. CSA is a problem more likely to occur in men than women.⁸  

• Heart disorders. If you have had problems with your heart, such as heart failure, the risk of CSA may increase.¹⁰  

• Opioid medications. Prescription medicines have been found to increase the risk of CSA.¹¹  

Mixed sleep apnea  

The third type of sleep apnea, MSA, is a mix of OSA and CSA. It is also referred to as complex sleep apnea.⁷  

Treatments for sleep-related conditions  

Whether you are dealing with OSA, CSA or both types at the same time, identifying the underlying cause is essential for treating your sleep apnea successfully. That is why it is important to talk with your doctor about any medical conditions, either past or present, as one of these could be the reason for your condition.    

To make an accurate assessment, your healthcare professional may recommend an overnight sleep study to analyse your breathing and sleep patterns. If you are subsequently diagnosed with sleep apnea, there are several treatment options available that can help improve your sleep as well as reduce the risk of long-term health problems.