Sleep Apnea Diagnosis

Sleep Apnea Diagnosis: A Step-by-Step Process

The diagnosis of Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) follows a structured two-stage process: a comprehensive clinical assessment, followed by a specialist sleep study to objectively confirm the disorder. This approach ensures an accurate diagnosis and care tailored to your situation. The sleep study is painless and non-invasive and can be performed either at home or in a specialist centre.

Initial Medical Consultation

The medical consultation is the first stage of diagnosis. The physician collects detailed information about your symptoms and daily life to assess the likelihood of sleep apnea. This stage determines whether a sleep study should be performed.

Three key points will be discussed:

• Direct discussion with you and your family or partner
• Detailed assessment of your symptoms (night-time, daytime and overall impact)
• Information about your sleep diary

Discussion with the Physician and Your Family or Partner

The physician speaks directly with you and, where possible, with a family member or partner. This is crucial because those close to you often notice signs that you may not perceive yourself, particularly pauses in breathing and loud snoring during the night. These objective observations strongly support a possible diagnosis of sleep apnea.

Symptom Assessment

The physician assesses three categories of symptoms: night-time signs (loud snoring, pauses in breathing, choking and restless sleep), daytime problems (persistent fatigue, excessive sleepiness, morning headaches and difficulty concentrating) and the overall impact on quality of life. According to HAS recommendations, diagnosis is based on the combination of at least three specific clinical symptoms and an apnea-hypopnea index (AHI) measured by a sleep study.

Sleep Diary

The physician may suggest keeping a sleep diary for two to four weeks. Each morning, record your bedtime and sleep-onset time, waking time, perceived sleep quality and any symptoms experienced (night-time awakenings, sweating, fatigue on waking and daytime sleepiness). This simple tool documents your sleep patterns and helps determine the most appropriate test.

Sleep Studies: Two Options

Two types of sleep study can confirm a diagnosis of sleep apnea:

• Overnight respiratory polygraphy — Simplified home test (first-line option)
• Polysomnography — Comprehensive test in a sleep laboratory (if required)

The choice depends on your clinical situation and the complexity of your case.

Home Overnight Respiratory Polygraphy

Respiratory polygraphy is generally the first test prescribed. This simplified portable test is performed at home over a full night. The sleep centre provides a small device with sensors that you attach before going to sleep. These non-invasive sensors record breathing (nasal airflow and chest and abdominal movements) and blood oxygen saturation during sleep. You return the equipment to the centre the following day.

The team downloads and analyses the data using standardized criteria, determining the number of apneas and hypopneas per hour: the apnea-hypopnea index (AHI). Polygraphy is simple and effective and can diagnose most cases.

Polysomnography in a Specialist Centre

Polysomnography is a more comprehensive test: it combines respiratory polygraphy with recordings of brain activity (EEG), eye movements, cardiac activity (ECG) and muscle activity (EMG). It also records respiratory movements and blood oxygen saturation.

The test lasts a full night, usually in a room at a specialist centre, but it can also be performed at home on an outpatient basis. It is prescribed when polygraphy results are inconclusive, when there is doubt about the obstructive nature of the apnea, or when other associated sleep disorders are suspected (restless legs syndrome, parasomnias or cardiac arrhythmias).

Interpreting Results: The Apnea-Hypopnea Index (AHI)

After the sleep study, a specialist physician analyses the data and produces a detailed report.

Key parameter: The apnea-hypopnea index (AHI), which measures the total number of apneas (complete pauses in breathing) and hypopneas (partial reductions in breathing) per hour of sleep.

Classification according to AHI:

• AHI < 5: Normal — no sleep apnea
• AHI 5–15: Mild sleep apnea
• AHI 15–30: Moderate sleep apnea
• AHI ≥ 30: Severe sleep apnea

The report also assesses blood oxygen saturation and, where relevant, heart rhythm. Based on these findings, the physician discusses treatment options suited to the severity of your condition and your symptoms.

Treatment Adaptation Based on the Diagnosis

Once all tests have been completed and analysed, your physician brings the results together to establish a precise, personalized diagnosis. The detailed polysomnography report specifies not only your AHI, but also the characteristics of your apneas: their type (obstructive due to upper-airway blockage, central due to absent respiratory effort, or mixed), sleep fragmentation including the number of micro-arousals and overall sleep quality, and minimum oxygen saturation indicating the degree of nocturnal desaturation.

These details allow the physician to recommend the treatment best suited to your specific case. Long-term effectiveness depends both on the type of treatment and on how acceptable it is to you personally. Regular adherence is essential for treatment success, and a thorough discussion with your physician about treatment options and your preferences is crucial.

Treatment Options According to Severity

Treatment is recommended when the AHI is above 15 and is associated with at least three specific symptoms (daytime sleepiness, severe daily snoring, choking sensations, daytime fatigue, nocturia or morning headaches), or in severe sleep apnea (AHI ≥ 30), regardless of symptom severity.

The main treatment options are Continuous Positive Airway Pressure (CPAP) as the standard treatment, a mandibular advancement device (MAD) when CPAP is not tolerated or for mild to moderate apnea, and management of aggravating factors (obesity, sleeping position and alcohol consumption) through lifestyle advice. Your physician will guide you towards the treatment best suited to your situation.

Common Mistakes in the Diagnostic Pathway

Several mistakes can delay or complicate diagnosis. The main ones to avoid are ignoring early signs and postponing consultation (the earlier the diagnosis, the better the prognosis, according to HAS), dismissing observations from family members or your partner (observed pauses in breathing are an important indicator), stopping after an initial “normal” test (normal polygraphy does not rule out mild apnea and polysomnography may be required), and failing to describe symptoms clearly to the physician (be precise about fatigue, snoring and observed pauses in breathing).

Practical tip: Prepare a list of your symptoms before the consultation, noting their frequency and intensity. If possible, bring your partner or someone close to you who has observed pauses in your breathing. These objective observations are crucial for an accurate diagnosis.

Next Steps

Once the diagnosis has been confirmed and the severity of your sleep apnea assessed, you can explore treatment options. Learn how CPAP, mandibular advancement devices and other therapeutic approaches can improve your sleep and quality of life in our complete guide to sleep apnea treatment.

Official and Scientific Resources

• HAS – Sleep apnea: definition, diagnosis and management
• Ameli – Sleep apnea: symptoms, diagnosis and progression

This content is provided for informational purposes only and is not a substitute for medical advice. Consult your sleep specialist to discuss your symptoms and diagnosis.