What sleep apnea is
During sleep, the muscles of the throat relax. In some people that relaxation is enough to narrow or completely close the airway. Airflow stops, blood oxygen falls and the brain responds with a micro-awakening to restart breathing.
This cycle can repeat five, thirty or more than sixty times an hour. In most cases the person remembers none of these awakenings — only that they wake up tired, every day, without understanding why.
Severity is measured by the apnea-hypopnea index (AHI), the average number of breathing pauses per hour of sleep. That number, obtained in a sleep study, is what defines whether apnea is mild, moderate or severe.
Most common symptoms
The signs appear at night and during the day. Often it is the bed partner who raises the alarm.
- Loud, habitual snoring, sometimes interrupted by silences
- Pauses in breathing witnessed by someone else
- Waking with a choking or gasping sensation
- Restless sleep and frequent night-time trips to the bathroom
- Dry mouth and headache on waking
- Excessive daytime sleepiness, especially in monotonous situations
- Difficulty concentrating, memory lapses and irritability
- Reduced libido
Causes and risk factors
Apnea results from the combination of airway anatomy and factors that worsen its collapse during sleep. Having risk factors does not mean having apnea — it means it is worth investigating.
- Excess weight and obesity, especially with fat around the neck
- Increased neck circumference
- Age over 50
- Male sex, and women after menopause
- Anatomical features: large tonsils, deviated nasal septum, receding upper or lower jaw
- Evening alcohol and sedative use
- Smoking and chronic nasal obstruction
- Family history of sleep apnea
- Hypothyroidism and other endocrine conditions
Why it should not go untreated
Each breathing pause causes a drop in oxygen and an activation of the nervous system. Repeated every night for years, this has measurable consequences: untreated apnea is associated with hard-to-control high blood pressure, arrhythmias, heart attack, stroke, type 2 diabetes and depression.
There is also an immediate risk: sleepiness at the wheel. In Portugal, untreated sleep apnea is grounds for driving restrictions, and effective treatment allows fitness to drive to be restored.
How it is diagnosed
Diagnosis starts with a sleep medicine consultation reviewing symptoms, habits, medication and medical history. Screening questionnaires such as STOP-Bang help estimate risk — but they do not diagnose.
Confirmation requires a sleep study. In most cases it can be done at home, in your own bed: a home cardiorespiratory study records airflow, respiratory effort, oxygen, heart rate, body position and snoring over one night. More complex cases may require polysomnography.
The recording is then read by a specialist, who calculates the apnea-hypopnea index and explains the result in consultation. On average, the path from first contact to diagnosis takes about 15 days.
Treatment options
CPAP
A small device delivers pressurised air through a mask, keeping the airway open. It is the first-line treatment in moderate to severe apnea and the effect is often felt within the first weeks. We do not sell equipment: we prescribe, adapt and follow up, and the device is supplied by home respiratory care companies.
Mandibular advancement device
A custom-made oral appliance that slightly advances the lower jaw and widens the airway. It is an effective alternative in mild to moderate apnea and for people who cannot tolerate CPAP.
Positional therapy
In some people apnea occurs almost only when lying on the back. In these cases, devices that prevent that position can significantly reduce the number of events.
Lifestyle measures
Weight reduction, avoiding alcohol and sedatives at night, treating nasal obstruction and stopping smoking all improve apnea severity and enhance any other treatment.
Surgery
In selected cases — very enlarged tonsils, marked nasal obstruction or facial skeletal abnormalities — surgical correction may be indicated, alone or as a complement.
When to seek help
Book an assessment if you snore habitually, if someone has noticed you pause your breathing, or if you wake up tired and feel sleepy during the day even after sleeping the hours you should.
The assessment is even more urgent if you have hard-to-control high blood pressure, arrhythmias, diabetes, or if you have fallen asleep — or nearly fallen asleep — while driving.
Frequently asked questions
Not necessarily. Some people snore without having apnea. But habitual, loud snoring is the most frequent sign of obstructive apnea, especially when accompanied by daytime tiredness or breathing pauses witnessed by someone else. A sleep study settles the question.
CPAP treats apnea while it is being used — it does not cure it. In many cases it is kept long term, but the need is reassessed periodically: significant weight loss, surgery or treating a nasal obstruction can change the picture and, in some cases, allow it to be reduced or stopped.
In most cases, no. The home cardiorespiratory study is suitable for diagnosing apnea and has the advantage of recording your real sleep, at home. We reserve polysomnography for more complex clinical situations.
Educational information reviewed by our clinical team. It does not replace an individual medical consultation.