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Polysomnography

Polysomnography — a sleep study that monitors breathing, heart rhythm, and brain activity during sleep.

A comprehensive overnight sleep recording for the diagnosis of obstructive sleep apnea and other sleep disorders in patients with snoring, witnessed apneas, and daytime sleepiness.

Indication

  • Persistent snoring with witnessed pauses in breathing
  • Excessive daytime sleepiness, attention and memory difficulties
  • Uncontrolled hypertension, atrial fibrillation, or treatment-resistant heart failure
  • Morning headaches, dry mouth, and unrefreshing awakening
  • Anatomical risk factors such as obesity, large neck circumference, or retrognathia
  • Suspicion of restless legs syndrome, narcolepsy, or parasomnia

Preparation

  • Avoidance of coffee, tea, and energy drinks from the afternoon of the test day
  • Hair and skin should be clean; no creams or oils should be used
  • Routinely used medications are continued according to physician guidance
  • Arrival at the laboratory at the usual bedtime in the evening
  • Bringing pajamas, slippers, and any necessary personal care items

How it's performed

  1. The patient is settled in a private room in the sleep laboratory
  2. Electrodes are placed for brain waves (EEG), eye movements (EOG), and chin and leg muscles (EMG)
  3. Sensors for respiratory effort, airflow, oxygen saturation, and ECG are attached
  4. Sleep stages, respiratory events, and oxygen levels are recorded throughout the night
  5. When indicated, CPAP titration is performed on a second night or during the same night
  6. Data are scored and reported by a sleep specialist

Post-procedure

  • Lifestyle recommendations based on results (weight loss, limiting alcohol and sedatives, side sleeping)
  • Planning of CPAP, BiPAP, or oral appliance therapy in suitable cases
  • Assessment of device adherence and effectiveness at 1, 3, and 12 months
  • Review of accompanying hypertension, diabetes, and cardiac disease management
  • Surgical or hypoglossal nerve stimulation consultation if treatment response is insufficient

Risks

  • Transient skin irritation related to electrode adhesives
  • Difficulty falling asleep due to the unfamiliar environment (first-night effect)
  • Reduced recording quality from sensor displacement
  • Transient nasal congestion, dry mouth, or aerophagia during CPAP titration
  • Possibility of electrode detachment in restless patients during recording

FAQ

Is the test painful?

Polysomnography is a painless test. Sensors are held to the skin with adhesive; only a mild sensation may occur when they are removed after the test.

What if I cannot sleep at all — is the test invalid?

Generally a 4-hour stretch of quality sleep is sufficient for interpretation. If sleep is too brief, the test can be rescheduled.

Will I need to use a CPAP device for life?

The need for the device depends on the severity of obstructive sleep apnea and accompanying conditions. With weight loss, an oral appliance, or surgical options, the need for CPAP may decrease; the decision is made together with physician follow-up.

Is this test performed in children too?

Yes — polysomnography can be performed in children with snoring, attention problems, or growth delay using appropriate protocols in a pediatric sleep laboratory.