{"id":6767,"date":"2026-06-06T20:27:27","date_gmt":"2026-06-06T19:27:27","guid":{"rendered":"https:\/\/neuropsiquiatria.pt\/?p=6767"},"modified":"2026-06-06T20:27:28","modified_gmt":"2026-06-06T19:27:28","slug":"como-se-deteta-a-apneia-do-sono-exames-e-diagnostico","status":"publish","type":"post","link":"https:\/\/neuropsiquiatria.pt\/en\/como-se-deteta-a-apneia-do-sono-exames-e-diagnostico\/","title":{"rendered":"How is Sleep Apnoea Detected? Tests and Diagnosis"},"content":{"rendered":"<div data-elementor-type=\"wp-post\" data-elementor-id=\"6767\" class=\"elementor elementor-6767\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3b4cb22e e-flex e-con-boxed e-con e-parent\" data-id=\"3b4cb22e\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a756867 elementor-widget elementor-widget-text-editor\" data-id=\"a756867\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>Short answer<\/strong>: sleep apnoea is diagnosed through a clinical assessment at the doctor\u2019s surgery and a sleep study known as <em>Polysomnography<\/em>, which monitors breathing, brain waves and other parameters throughout the night.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6081924 elementor-widget elementor-widget-post-info\" data-id=\"6081924\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"post-info.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<ul class=\"elementor-inline-items elementor-icon-list-items elementor-post-info\">\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item elementor-repeater-item-87d2c88 elementor-inline-item\" itemprop=\"datePublished\">\n\t\t\t\t\t\t<a href=\"https:\/\/neuropsiquiatria.pt\/en\/2026\/06\/06\/\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-calendar\" viewbox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M12 192h424c6.6 0 12 5.4 12 12v260c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V204c0-6.6 5.4-12 12-12zm436-44v-36c0-26.5-21.5-48-48-48h-48V12c0-6.6-5.4-12-12-12h-40c-6.6 0-12 5.4-12 12v52H160V12c0-6.6-5.4-12-12-12h-40c-6.6 0-12 5.4-12 12v52H48C21.5 64 0 85.5 0 112v36c0 6.6 5.4 12 12 12h424c6.6 0 12-5.4 12-12z\"><\/path><\/svg>\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text elementor-post-info__item elementor-post-info__item--type-date\">\n\t\t\t\t\t\t\t\t\t\t<time>6 June 2026<\/time>\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3439875e elementor-widget elementor-widget-text-editor\" data-id=\"3439875e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-6914 size-full\" src=\"https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring.webp\" alt=\"Ilustra\u00e7\u00e3o de um homem a ressonar na cama, deitado de costas, com a boca aberta e os olhos fechados, sugerindo um epis\u00f3dio de apneia do sono ou ressonar profundo.\" width=\"1448\" height=\"1086\" srcset=\"https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring.webp 1448w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring-300x225.webp 300w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring-1024x768.webp 1024w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring-768x576.webp 768w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/05\/sleep-apnea-snoring-16x12.webp 16w\" sizes=\"(max-width: 1448px) 100vw, 1448px\" \/><\/p><h2>Suspected Sleep Apnoea: When Should You Seek Medical Help?<\/h2><p>Waking up tired every day, feeling constantly sleepy, or hearing a family member say that \u201c<strong>hold your breath<\/strong>\u201dduring sleep are signs that <strong>should not be ignored<\/strong>.<\/p><p>If you\u2019ve already read about the <a href=\"https:\/\/neuropsiquiatria.pt\/en\/falta-de-ar-ao-dormir\/\"><strong>symptoms and causes of sleep apnoea and nocturnal dyspnoea<\/strong><\/a> and if you recognised some of them, this article is the next step: <strong>understand what happens once you arrive at the appointment, what tests are involved and what the results mean<\/strong>.<\/p><div class=\"nota-importante\">The rate of underdiagnosis of sleep apnoea in Portugal is around <strong>80%<\/strong> \u2014 less than <strong>20%<\/strong> of cases are treated. The symptoms are often mistaken for tiredness or stress. <strong>Early diagnosis improves the chances of a successful outcome.<\/strong><\/div><h2>How is the initial clinical assessment for sleep apnoea carried out?<\/h2><p>A specialist sleep consultation \u2014 usually with a <strong><a href=\"https:\/\/neuropsiquiatria.pt\/en\/neurologia\/\">neurologist<\/a><\/strong> or a neuropsychiatrist \u2014 is the starting point.<\/p><p>The doctor collects information about the <strong>sleeping habits<\/strong>, <strong>medical history<\/strong> e <strong>risk factors<\/strong>, and may appeal to <a href=\"https:\/\/www.msdmanuals.com\/pt\/profissional\/multimedia\/table\/classifica%C3%A7%C3%A3o-de-risco-stop-bang-para-apneia-obstrutiva-do-sono\"><strong>STOP-BANG questionnaire<\/strong><\/a>: an internationally validated screening tool comprising eight objective criteria.<\/p><p>The acronym describes the criteria:<\/p><ul><li><strong>to snore loudly<\/strong> (<em>Snoring<\/em>)<\/li><li><strong> daytime tiredness<\/strong> (<em>Tired<\/em>)<\/li><li><strong> pauses observed by others<\/strong> (<em>Observed<\/em>)<\/li><li><strong> high blood pressure<\/strong> (<em>Pressure<\/em>)<\/li><li><strong> High BMI<\/strong> (<em>BMI<\/em>)<\/li><li><strong> aged over 50<\/strong> (<em>Age<\/em>)<\/li><li><strong> neck circumference over 40 cm<\/strong> (<em>Neck<\/em>)<\/li><li><strong>male<\/strong> (<em>Gender<\/em>)<\/li><\/ul><p>A score of <strong>3 or more positive criteria<\/strong> places the patient in the intermediate to high-risk category \u2014 and justifies further tests.<\/p><h2>What is Polysomnography and How Does This Sleep Test Work?<\/h2><p>A <strong>polysomnography<\/strong> is the gold standard test for diagnosing apnoea \u2014 the so-called \u201c<em>gold standard<\/em>\u201d in the assessment of sleep-related breathing disorders.<\/p><p>Over the course of a whole night, it simultaneously records:<\/p><ul><li><strong>brain activity<\/strong> (EEG)<\/li><li><strong> eye movements<\/strong> (EOG)<\/li><li><strong> muscle activity<\/strong> (EMG)<\/li><li><strong> heart rate<\/strong><\/li><li><strong> nasal and oral airflow<\/strong><\/li><li><strong> blood oxygen saturation<\/strong><\/li><li><strong> respiratory effort and body position<\/strong><\/li><\/ul><p>The exam is <strong>completely non-invasive<\/strong> \u2014 all the sensors are placed on the surface of the body, and most people are able to fall asleep as normal.<\/p><div class=\"dica-valiosa\">If you are having a polysomnography, avoid caffeine and alcohol on the day of the test and stick to your usual sleep routine. The more the night of the test resembles a normal night, the more reliable the results will be.<\/div><div><img decoding=\"async\" class=\"alignleft wp-image-7007\" src=\"https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia.webp\" alt=\"Homem a dormir em laborat\u00f3rio durante exame de polissonografia, rodeado por equipamentos m\u00e9dicos e gr\u00e1ficos digitais. Exame do sono realizado para o diagn\u00f3stico de problemas como a apneia do sono.\" width=\"800\" height=\"537\" srcset=\"https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia.webp 2528w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-300x201.webp 300w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-1024x687.webp 1024w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-768x515.webp 768w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-1536x1030.webp 1536w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-2048x1374.webp 2048w, https:\/\/neuropsiquiatria.pt\/wp-content\/uploads\/2026\/06\/exame-do-sono-polissonografia-18x12.webp 18w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/div><h3>Type 1, 2, 3 and 4 Polysomnography: What Is the Difference Between Them?<\/h3><p>There are four types of polysomnography, classified by <strong>number of parameters monitored<\/strong> and by the <strong>venue<\/strong>. The choice depends on the clinical suspicion and the complexity of the case.<\/p><p>A <strong>type 1<\/strong> is carried out in a sleep laboratory under the continuous supervision of a technician, recording at least<strong> 7 signal channels<\/strong> \u2014 brain activity, eye movements, muscle movements, heart rate, respiratory flow and oximetry. It is the study of <strong>greater sensitivity<\/strong> e <strong>lower failure rate<\/strong>, recommended in more complex cases or when other methods have proved inconclusive.<\/p><p>A <strong>type 2<\/strong> monitors the same parameters as the Type 1 model \u2014 at least 7 channels \u2014 but is <strong>carried out at home<\/strong>, without the presence of a technician. It is the most comprehensive option for home-based monitoring, useful when the patient is unable to sleep in the laboratory but a more complex condition is suspected.<\/p><p>A <strong>type 3<\/strong> \u2014 also known as cardiorespiratory polygraphy \u2014 records between 4 and 7 channels, <strong>no brain activity detected<\/strong>. The focus is on assessing obstructive sleep apnoea: it monitors airflow, snoring, respiratory effort, oxygenation and body position. It is carried out at home and <strong>shorter waiting times<\/strong> and is sufficient to diagnose apnoea in most cases.<\/p><p>A <strong>type 4<\/strong> uses only 1 or 2 channels \u2014 typically <strong>pulse oximetry<\/strong> (blood oxygen levels) and <strong>heart rate<\/strong>. It is the method <strong>more simplified<\/strong>, used as an initial screening tool or in specific contexts involving excessive sleepiness. <strong>It does not replace the previous classifications in the formal diagnosis of apnoea<\/strong>.<\/p><p>The doctor will advise on the most appropriate approach for each clinical situation.<\/p><h3>What does the Apnoea-Hypopnoea Index (AHI) mean?<\/h3><p>The key finding of polysomnography is the <a href=\"https:\/\/www.resmed.com.br\/blog\/saiba-o-que-significa-sua-pontuacao-iah\"><strong>Apnoea-Hypopnoea Index (AHI)<\/strong><\/a> \u2014 the number of abnormal breathing events per hour of sleep. It is this figure that determines the severity and guides treatment:<\/p><ul><li><strong>IAH less than 5<\/strong> \u2014 normal<\/li><li><strong>IAH between 5 and 15<\/strong> \u2014 mild apnoea<\/li><li><strong>IAH between 15 and 30<\/strong> \u2014 moderate sleep apnoea<\/li><li><strong>IAH greater than 30<\/strong> \u2014 severe apnoea<\/li><\/ul><p>A <strong>hypopnoea<\/strong> This corresponds to a partial reduction in airflow \u2014 sufficient to lower blood oxygen saturation or trigger a micro-awake state, with a real impact on rest.<\/p><h2>After the Diagnosis: What Are the Treatment Options for Sleep Apnoea?<\/h2><p>Once the IAH has been determined, the doctor draws up a treatment plan. To <strong>moderate to severe sleep apnoea<\/strong>, the first-line treatment is <strong>CPAP<\/strong> (<em>Continuous Positive Airway Pressure<\/em>) \u2014 a nasal mask that keeps the airways open by delivering a flow of pressurised air.<\/p><p>In Portugal, it is <strong>fully funded by the NHS<\/strong> in cases where there is a clinical indication.<br \/>To <strong>mild apnoea<\/strong>, or when CPAP is not tolerated, there are alternatives: <strong>mandibular advancement prostheses<\/strong>, <strong>surgical procedure<\/strong> in cases of specific anatomical obstruction, and <strong>lifestyle changes<\/strong>.<\/p><p>Losing weight, avoiding alcohol in the evening, and sleeping on your side can significantly reduce OSA.<\/p><h2>The Neurological Impact of Untreated Sleep Apnoea: Why a Comprehensive Assessment Is Important<\/h2><p>Sleep apnoea <strong>it is not just a respiratory problem<\/strong>. Each episode causes a drop in oxygen levels and a micro-awakening of the brain \u2014 imperceptible on its own, but <strong>very harmful to health<\/strong> in the long term.<\/p><p>Over time, memory problems, slower cognitive processing, difficulty concentrating and emotional instability may develop.<\/p><p>In <strong>NeuroPsyque<\/strong>, each case is assessed holistically, with particular attention paid to neurological consequences. The <a href=\"https:\/\/neuropsiquiatria.pt\/en\/neurofeedback-e-qeeg\/\"><strong>Neurofeedback<\/strong><\/a> can be used as a complement to conventional treatment, training the brain to <strong>establish more stable and restorative sleep patterns<\/strong>, thereby avoiding the problem of becoming dependent on sleeping pills.<\/p><div class=\"pontos-chave\"><h2>\ud83e\udde0 Key Points to Retain<\/h2><ul><li>The rate of underdiagnosis of sleep apnoea in Portugal is around 80% \u2014 the majority of cases are never assessed.<\/li><li>The STOP-BANG questionnaire comprises eight objective criteria; a score of \u22653 warrants further investigation.<\/li><li>Polysomnography simultaneously monitors brain, heart and respiratory activity \u2014 it is the gold standard test for diagnosis.<\/li><li>It can be carried out in a laboratory (type 1) or at home using a portable device (type 3), as directed by a doctor.<\/li><li>The IAH classifies severity as mild (5\u201315), moderate (15\u201330) or severe (&gt;30) \u2014 and directly guides the choice of treatment.<\/li><li>CPAP is covered by the National Health Service in Portugal; for mild sleep apnoea, mandibular advancement devices and lifestyle changes are valid alternatives.<\/li><li>Untreated sleep apnoea has a progressive neurological impact \u2014 the comprehensive assessment at NeuroPsyque includes an evaluation of the cognitive effects.<\/li><\/ul><\/div><h2><span style=\"text-decoration: underline;\">FAQs - Frequently Asked Questions<\/span><\/h2><h3>What is the STOP-BANG questionnaire and how is it used in diagnosis?<\/h3><p>It is a screening tool based on eight objective clinical criteria, used during consultations to estimate the likelihood of sleep apnoea before proceeding to further tests. A score of 3 or more indicates an intermediate to high risk.<\/p><h3>How long does a polysomnography take?<\/h3><p>The test takes place over a full night. In the home version (type 3), the patient fits the device at home and returns it the following day. The results are available within a few working days.<\/p><h3>Is home polysomnography as reliable as laboratory-based polysomnography?<\/h3><p>For the diagnosis of apnoea without complex comorbidities, type 3 has comparable sensitivity. Where other sleep disorders are suspected, a laboratory study is preferable as it monitors more parameters.<\/p><h3>Is CPAP covered by the National Health Service in Portugal?<\/h3><p>Yes, in all cases where there is a clinical indication \u2014 moderate to severe sleep apnoea confirmed by polysomnography. The process involves a medical prescription and follow-up by an accredited organisation.<\/p><h3>Can mild sleep apnoea be treated without CPAP?<\/h3><p>In many cases, yes. Losing weight, avoiding alcohol in the evening and sleeping on your side can significantly reduce OSA. Mandibular advancement devices are equally effective for mild to moderate apnoea.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Resposta curta: a apneia do sono deteta-se atrav\u00e9s de avalia\u00e7\u00e3o cl\u00ednica em consult\u00f3rio e de um exame do sono chamado Polissonografia, que monitoriza a respira\u00e7\u00e3o, as ondas cerebrais e outros par\u00e2metros durante a noite. Suspeita de Apneia do Sono: Quando Deve Procurar Ajuda M\u00e9dica? Acordar cansado todos os dias, sentir sonol\u00eancia persistente ou ouvir de [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6914,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[45],"class_list":["post-6767","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-geral","tag-novo-layout"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/posts\/6767","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/comments?post=6767"}],"version-history":[{"count":26,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/posts\/6767\/revisions"}],"predecessor-version":[{"id":7013,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/posts\/6767\/revisions\/7013"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/media\/6914"}],"wp:attachment":[{"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/media?parent=6767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/categories?post=6767"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/neuropsiquiatria.pt\/en\/wp-json\/wp\/v2\/tags?post=6767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}