Sleep problems are quite common among people of all ages. They are a collection of problems that disrupt how we normally sleep. They are very common and can cause issues with our physical and mental well-being, social lives, and emotions. Not getting enough or restful sleep can affect our overall health, safety, and how we enjoy life.
To identify different sleep disorders, doctors perform a test called polysomnography (PSG) while you are fast asleep. During this test, a polysomnography technologist will carefully monitor you as you sleep and gather data about your sleep patterns. This information is crucial in understanding how you sleep and identifying any potential sleep disorders you may have.
During polysomnography, important information is recorded while you sleep, including brain waves, blood oxygen levels, breathing, and heart rate. In this procedure, leg and eye movements are also measured. This test is usually done in a hospital or a sleep centre. Typically, polysomnography is done at night, but people who work night shifts can do it during the day. A sleep study helps diagnose sleep disorders and create a treatment strategy accordingly. It can also be used to modify your current treatment. In certain cases, sleep studies can be conducted in the comfort of your own home. These tests are commonly used to diagnose obstructive sleep apnoea. These tests involve the use of different devices equipped with various sensors to monitor your breathing rate, airflow, heart rate, oxygen levels, and, in some cases, even provide insights into blood vessels.
Why is a Polysomnography (Sleep Study Test) Done?
Polysomnography is a method used to monitor your sleep cycles and stages. It helps identify any disruptions or reasons for changes in your sleeping patterns. When you fall asleep, the process usually starts with a stage called non-rapid eye movement (NREM) sleep, where brain waves slow down. During a sleep study, your brain activity is recorded using a device called an electroencephalogram (EEG). It helps track your sleep stages.
After approximately one to two hours of NREM sleep, your brain becomes more active, and you transition into a phase known as rapid eye movement (REM) sleep. This is when your eyes move quickly and most of your dreaming occurs. Throughout the night, you experience multiple sleep cycles, shifting between NREM and REM sleep approximately every 90 minutes. However, sleep disorders can disrupt this natural sleep pattern and affect the quality of your sleep.
A sleep study test is recommended if you have any of the following sleep disorders:
- Sleep apnoea involves the repeated interruption of breathing during sleep.
- Periodic limb movement disorder is a sleep disorder characterised by involuntary leg movements, including flexing and extending the legs in sleep. This disorder is occasionally linked to restless leg syndrome, a condition characterised by an uncontrollable desire to move the legs when awake. Restless legs syndrome commonly occurs in the evenings or before bedtime.
- Narcolepsy is a sleep disorder where individuals experience excessive daytime sleepiness and have the tendency to fall asleep rapidly.
- REM sleep behaviour disorder is a sleep disorder characterised by the enactment of dreams while sleeping. It involves engaging in unusual behaviours such as moving around, walking, or exhibiting rhythmic movements while sleeping.
- Unexplained persistent insomnia refers to a condition where individuals have difficulty either staying asleep or falling asleep without a clear cause.
Preparation Required for a Polysomnography Test
To prepare for an overnight sleep study, it is important to follow these guidelines:
- Avoid caffeine: Refrain from consuming caffeine in the afternoon or evening before the study. This includes beverages such as coffee, tea, cola, and foods containing chocolate. Also, avoid alcohol, as it can disrupt your sleep.
- Limit napping: Try not to take any naps on the day of the sleep study to ensure you can fall asleep during the test.
- Hair care: Before heading to the sleep centre, wash your hair using only shampoo. Make sure your hair is dry and avoid using hair sprays, oils, or gels as they may interfere with the sensors used during the study.
- Pack overnight essentials: When preparing for an overnight sleep study, it is recommended to pack an overnight bag with essential items. Remember to include comfortable pyjamas, an extra set of clothes for the morning, and similar items you would take for a hotel stay. Bringing your pillow is also an option if desired. Don’t forget to pack any necessary medications you may need during your time away from home.
- Inform the sleep centre: If you have any special needs or concerns, inform the staff at the sleep centre in advance. They are there to assist you and ensure your comfort and relaxation throughout the study.
- Medication disclosure: It is crucial to inform your sleep specialist about all the medications you are taking, including both prescribed and over-the-counter drugs. This includes common cold medicines and pain relievers. Some medications can influence your sleep and impact the results of the study. Depending on your situation, you may need to gradually discontinue certain medications in the days leading up to the sleep study. Your doctor will determine whether this is necessary for you. It is important not to stop taking any prescribed medication without consulting your sleep specialist first.
What to Expect During the Polysomnography Test?
If you are undergoing a Polysomnography test at a sleep centre, you will arrive in the evening and spend the night at the examination centre. You are allowed to bring the essentials you use for your sleep routine and can sleep in your nightclothes. For a home test, you should follow your usual bedtime routine. You will need to apply the sensors to your body and activate the device according to the provided instructions.
At a sleep centre, the room where the Polysomnography is conducted is designed in a way that has a dim light and is quiet during the test, and you will have the room to yourself. The room usually includes a video camera, allowing the technologists to monitor the room. Additionally, an audio unit is present, enabling communication between you and the technologists from their monitoring room.
Once you are prepared for bed, a technologist will apply sensors to specific areas of your body, including your temples, scalp, legs, and chest. The sensors used in the sleep study are connected to a computer using wires. These wires are long so that you can move freely and comfortably in bed. Furthermore, a clip will be attached to either your ear or finger to monitor the oxygen level inside your blood.
During your sleep, a technician carefully observes and tracks various aspects, including:
- Activity in your brain
- Movements of your eyes
- Rate of your heart
- The pattern of your breathing
- Level of oxygen in your blood
- Position of your body
- Movements of your chest and abdomen
- Movements of your limbs
- Sounds such as snoring
The technologist will continuously monitor these factors to gather essential information about your sleep patterns and any potential sleep disorders.
What to Expect After the Polysomnography Test?
After completing the polysomnography test, there are a few things you can expect. The sensors and wires attached to your body will be removed by a sleep technologist. Analysing a sleep study is a complex and time-consuming process. The data generated from a typical study can span several pages and include information such as brain waves, eye movements, and breathing patterns. It requires extensive effort from a trained professional to accurately interpret the results.
A sleep technologist meticulously processes and scores the data for analysis. The scored results are handed over to a doctor, specifically a board-certified sleep specialist at an accredited centre, for further evaluation. The doctor carefully examines the study to determine the type of sleep problem you might be experiencing. Due to the intricacy and time involved, it usually takes several days for the results to be ready.
The doctor who requested the study will then discuss the findings with you in detail. They will discuss treatment options, if necessary, and address any questions or concerns you may have. This is an opportunity to gain a better understanding of your sleep health and develop a plan for improving your sleep quality. Remember to follow any recommendations or treatment plans provided by the sleep specialist. They are designed to help you achieve better sleep and overall well-being. If you have any ongoing concerns or difficulties with your sleep, it is important to communicate with your healthcare provider and seek their guidance.
Risks associated with the Polysomnography Test
The polysomnography test is generally considered safe, but there are a few potential risks and discomforts associated with it. It is important to be aware of these risks:
Skin irritation: The adhesive used to attach the sensors to your body may cause mild skin irritation or allergic reactions in some individuals. Inform the sleep technologist if you experience any discomfort or irritation during the test.
Discomfort: Having sensors and wires attached to your body while sleeping may cause some discomfort or make it challenging to find a comfortable sleeping position. However, sleep technologists will try to ensure your comfort as much as possible.
Sleep disruption: Being in an unfamiliar sleep environment or having sensors and wires attached to you can disrupt your sleep patterns, which may affect the accuracy of the test results. It is important to try to relax and follow your regular sleep routine as closely as possible.
If you have specific health conditions or take medications, inform your healthcare provider beforehand to minimise potential risks.
