A sleep study, medically known as a Polysomnography (PSG), is a non-invasive test used to record what happens in your body and brain while you sleep. It is the standard, definitive way to diagnose sleep disorders, most commonly Sleep Apnea.
What is the Purpose?
The main goal of a sleep study is to capture a full picture of your sleep cycle and identify any disruptions that prevent you from getting healthy, restorative rest.
The test helps doctors determine:
- If you have a sleep disorder (like Obstructive Sleep Apnea, Narcolepsy, or Periodic Limb Movement Disorder).
- The severity of the disorder (e.g., how often your breathing stops in an hour, which determines your AHI score).
- The most effective treatment (e.g., the correct pressure setting for a CPAP machine).
What Data Does a Sleep Study Record?
A sleep study uses sensors attached to your body to monitor several key physiological activities simultaneously:
| Measurement | What It Tracks | Why It’s Important |
| Brain Waves (EEG) | Electrical activity in the brain. | Determines when you fall asleep and what stage of sleep you are in (light, deep, or REM). |
| Eye Movements (EOG) | Movement of the muscles around the eyes. | Essential for identifying the REM stage, where vivid dreaming occurs. |
| Muscle Activity (EMG) | Chin muscle tone and leg movements. | Detects restlessness, teeth grinding, and muscle paralysis during REM. |
| Breathing Effort | Movement of the chest and abdomen. | Shows if you are trying to breathe even when air isn’t flowing (a sign of OSA). |
| Airflow | Air moving in and out of your nose and mouth. | Detects blockages, pauses, or shallow breathing (apneas and hypopneas). |
| Oxygen Saturation | The level of oxygen in your blood (measured with a finger clip). | Identifies dangerous drops in oxygen that occur when breathing is blocked. |
| Heart Rate (ECG) | Electrical activity of the heart. | Monitors the rhythm and rate, which often become irregular during apnea events. |
Where Can A Sleep Study Be Done?
Sleep studies can be conducted in two main settings:
- In-Lab Polysomnography (PSG): The traditional, comprehensive test done overnight in a specialized sleep center or hospital lab. This is the most thorough test, as a technician is present all night to monitor the data and ensure the sensors stay in place.
- At-Home Sleep Apnea Test (HSAT): A simplified test that a patient conducts themselves in their own bed. This is usually used only to screen for Obstructive Sleep Apnea (OSA) and is not as comprehensive as an in-lab study. At Sleeptopia, We do provide At Home Sleep Apnea Test to diagnose sleep apnea.
If you have been recommended for a sleep study, it is the most important step you can take toward getting a diagnosis and improving your overall health and energy levels.
