A sleep clinic is a specialized medical facility focused on diagnosing and treating a wide range of sleep disorders. People commonly seek out these centers when experiencing disruptive symptoms like chronic loud snoring, excessive daytime tiredness, or persistent difficulty falling or staying asleep. The clinic’s purpose is to objectively measure and analyze sleep patterns to pinpoint the exact cause of these nighttime disturbances.
The Initial Consultation and Evaluation
The process begins with a scheduled appointment with a sleep specialist, who may be a physician or a trained advanced practice provider. During this first visit, the provider conducts a comprehensive review of the patient’s medical history, paying close attention to existing conditions that might affect sleep. The specialist gathers detailed information about specific sleep habits and symptoms, including the duration of the problem and its impact on daily life.
A standard screening tool used here is the Epworth Sleepiness Scale (ESS), a short questionnaire where the patient rates their likelihood of dozing off in eight common situations. A total score on the ESS above 10 typically indicates excessive daytime sleepiness, suggesting a significant sleep issue may be present. Based on this information, the specialist determines whether a formal sleep study is warranted and decides on the appropriate type, such as an in-lab study or a home sleep apnea test.
The Overnight Sleep Study Procedure
The most common diagnostic test is an overnight sleep study, formally known as Polysomnography (PSG), the standard for comprehensive evaluation. The patient arrives at the sleep center in the evening and is shown to a private, comfortable bedroom. Before the study begins, a trained sleep technician applies a variety of sensors to the patient’s body using a mild adhesive or tape.
These sensors are connected by thin wires to a computer that records multiple physiological signals throughout the night. Electrodes placed on the scalp record brain waves (EEG) to identify different sleep stages, including light sleep, deep sleep, and Rapid Eye Movement (REM) sleep. Sensors near the eyes (EOG) track eye movements, while electrodes on the chin and legs (EMG) monitor muscle activity to detect limb movements associated with disorders like Restless Legs Syndrome.
Elastic bands are placed around the chest and abdomen to measure breathing effort and movement, while a sensor near the nose and mouth monitors airflow. A small clip on a finger or earlobe uses pulse oximetry to continuously measure blood oxygen saturation, a crucial metric for detecting breathing interruptions. Throughout the night, the technician monitors the patient from a separate control room using a low-light video camera and an audio system.
The wires are long enough to allow the patient to move and turn in bed. While the full in-lab PSG is the most comprehensive, a Home Sleep Apnea Test (HSAT) may be prescribed for patients with a high suspicion of Obstructive Sleep Apnea (OSA). The HSAT uses a portable device to record fewer channels, typically focusing on breathing, oxygen levels, and heart rate, and is performed in the patient’s own home.
Diagnosis, Treatment Recommendations, and Follow-Up
The morning after an overnight study, the collected data is analyzed by a specialist, who scores the recording for various events. Two of the most important metrics are the Apnea-Hypopnea Index (AHI) and the Respiratory Disturbance Index (RDI). The AHI calculates the average number of apneas (complete breathing cessations) and hypopneas (partial breathing reductions) per hour of sleep.
An AHI score of 5 to 15 events per hour typically indicates mild OSA, 15 to 30 suggests moderate severity, and an AHI greater than 30 is classified as severe. The RDI provides a broader view by including all apneas and hypopneas, plus subtle breathing disruptions called Respiratory Effort-Related Arousals (RERAs) that fragment sleep. A high RDI, even with a low AHI, can indicate Upper Airway Resistance Syndrome (UARS) or another form of sleep-disordered breathing.
Based on the full data analysis, the specialist provides an official diagnosis, which may include Obstructive Sleep Apnea, Narcolepsy, or Periodic Limb Movement Disorder. Treatment recommendations are then tailored to the specific disorder and its severity. For moderate to severe OSA, Positive Airway Pressure (PAP) therapy, such as Continuous Positive Airway Pressure (CPAP), is often recommended as the primary treatment to keep the airway open during sleep.
Alternative options may include a custom-fitted oral appliance, which repositions the jaw to ease breathing, or surgical procedures. Behavioral and lifestyle changes, such as weight loss or positional therapy, are frequently suggested as adjunctive measures. A follow-up appointment is then scheduled to discuss the results, initiate the chosen treatment plan, and ensure the patient understands how to manage their condition.