Insomnia and sleep apnoea, what’s the difference?

Knowing you have difficulties sleeping is one thing, but understanding why and what’s causing your sleep deprivation is another. Sleep disorders can have complex causes and serious health consequences if left unmanaged. For this reason, it’s very important to speak with a medical specialist who has a keen interest in sleep disorders in order to gain a thorough diagnosis and to discuss your best treatment options.

Use this guide to understand more about 2 common yet very different sleep disorders.


Insomnia is a sleep disorder that is defined by difficulty falling asleep and/or staying asleep. The American Sleep Association defines insomnia as either primary or secondary insomnia.

Primary insomnia: A person who suffers from primary insomnia is having sleep problems that are not directly associated with any other health condition or problem. Usually the cause of primary insomnia is not known.

Secondary insomnia: Is more prevalent than primary insomnia. People suffering secondary insomnia are having sleep problems because of some other reason. Often this can be an underlying health condition (like asthma, depression, arthritis, cancer, or heartburn); due to pain; or prescription medication or a or a substance they are using (like alcohol).

Individuals with primary and secondary insomnia present with similar symptoms. Sufferers experience the following symptoms with varying degrees of severity.

• Difficulty falling asleep
• Waking up often during the night and having trouble going back to sleep
• Waking up too early in the morning
• Feeling tired upon waking
• Sleepiness during the day
• General tiredness
• Irritability
• Difficulty concentrating and problems with memory
• Depression

Acute vs. Chronic Insomnia

Insomnia is also categorised by how long the sufferer experiences the symptoms; insomnia can be acute or chronic. The time and frequency a person suffers insomnia has an impact on the severity of the symptoms. Acute insomnia is only experienced over a short amount of time, while chronic insomnia can last over long periods and can have more detrimental health consequences. Acute insomnia can come and go, with periods of time when a person has no sleep issues at all. The National Sleep Foundation defines chronic insomnia as difficultly sleeping at least three nights per week for three months or longer.

What Causes Insomnia?

Causes of Primary Insomnia

The cause of primary insomnia is usually not fully known, and whether some people are more prone than others is still unclear. The American Sleep Association suggests factors such as long lasting stress, major emotional upset, travel, work and constantly disrupted sleep routines as often linked to episodes of primary insomnia. However, even when these causes go away, the insomnia might stay. Often people form habits to deal with the lack of sleep. Naps, going to bed early or worrying about sleep may hinder insomnia resolving, even when the initial stress is relieved.

Causes of Secondary Insomnia

Secondary insomnia is the symptom of an underlying cause. Often the initial concern can be an emotional or neurological factor or other medical disorder, even another sleep disorder.

Some emotional and neurological disorders that can cause insomnia include:

• Depression and anxiety
• Posttraumatic stress disorder
• Alzheimer’s and Parkinson’s disease are examples of common neurological disorders.
Other diseases and conditions associated with secondary insomnia are:
• Conditions that cause chronic pain, such as arthritis
• Conditions that cause difficulty breathing, such as asthma or heart failure
• Overactive thyroid
• Gastrointestinal disorders, such as heartburn
• Stroke

In addition, secondary insomnia can be a side effect of commonly used substances or medications including:

• Caffeine or other stimulants
• Tobacco or other products with nicotine
• Alcohol or other sedatives
• Certain asthma medicines (for example, theophylline) and some allergy and cold medicines
• Beta blockers (medicines used to treat heart conditions)

Sleep Apnoea

There are 2 types of Sleep Apnoea; Central Sleep Apnoea (CSA) and Obstructive Sleep Apnoea (OSA).

Central Sleep Apnoea

CSA is far less common and is defined by the Sleep Health Foundation as pauses in breathing efforts. About 10% of people with sleep difficulties have CSA. Essentially the body’s breathing receptors in the brain are dulled or less responsive to changes on CO2. The cause can be a myriad of things, including drugs and medication, weak respiratory muscles, stroke, heart failure or other neurological conditions.

Obstructive Sleep Apnoea

Obstructive Sleep Apnoea is more common and is the result of a physical blockage or narrowing of the airways. During sleep the muscles around the throat and airways relax, sometimes falling backward in the mouth. This “floppy” airway can easily become partially of fully blocked during inhalation especially. Exhalation usually creates enough pressure on the airway to force it open for a short time allowing air to escape. Airway pressure drops significantly for inhalation, and this can collapse the airway, either restricting or completing limiting inhalation causing apnoea. OSA can affect people at any age, even children, however more commonly middle aged men are most commonly affected. Being overweight is also closely associated with suffering OSA.


Some symptoms of CSA and OSA are similar and both can have equally severe health consequences if left untreated in the long term.

Symptoms in common:

• Waking tired
• Restless sleep and waking during the night
• Daytime fatigue and irritability

OSA can sometimes be easier to detect, particular by bed partners, family or friends. Loud snoring, gasping and gulping for air and choking are common indicators of OSA. Try our Obstructive Sleep Apnoea Risk Assesment.

Other common features of OSA include:

• Obesity (a major risk factor)
• Long-standing snoring and gulping
• Mouth breather
• Sleeps on their back
• Episode or stopping breathing noticed by bead partner
• Morning headache and/or dry mouth
• Excessive sleepiness during the day

Diagnosing Sleep Apnoea or Insomnia

The most reliable diagnosis for any sleep disorders is a sleep study also known as a polysomnography or PSG. A sleep study is a medical test that can be done in the home or by staying overnight in a specialised sleep clinic. Sleep is monitored closely to assist with the diagnosis of sleep problems. The findings of the overnight sleep study, along with a detailed medical history can be used to determine the type of sleep disorder (insomnia, sleep apnoea or another) you suffer and the severity. An oral exam performed by a specialist dentist can also be useful to determine if OSA is coming from an oral or dental cause.

To learn more about sleep studies you can read these links;

Sleep disorders are serious and can have severe long lasting health consequences. In 2012 an economic report commissioned by the Sleep Health Foundation, ”Re-awakening Australia – The Economic Cost of Sleep Disorders in Australia,” found that over 1.5 million adults or 9% of the Australian population suffers from disordered sleep. Professional bodies believe that many sleep disorders still go unreported or misdiagnosed. If you or a loved one snores loudly, or wakes up tired you can take simple steps. No it’s not normal! Speak to your GP or Sound Sleeper provider today.