Sleep Apnea: Symptoms, Diagnosis & Treatment Options

What is sleep apnea?

Sleep apnea is a common sleep disorder in which breathing repeatedly stops and starts during sleep. Each pause typically lasts 10 seconds or longer and ends with a brief micro-arousal — a partial wake that you usually don't remember but that fragments sleep and stresses the cardiovascular system.

It is estimated to affect around 1.5 million adults in the UK, and the majority remain undiagnosed. Sleep apnea is more common in men, in people who are overweight, and in adults aged 30–60, but it can affect any age — including children with enlarged tonsils.

The three types of sleep apnea

• Obstructive sleep apnea (OSA) — by far the most common, accounting for roughly 84% of cases. Caused by physical airway collapse: the throat muscles relax, soft tissue blocks the airway, and breathing pauses despite continued effort to breathe.
• Central sleep apnea (CSA) — the brain temporarily stops sending the signal to breathe. Less common, often linked to heart failure, stroke, or opioid medications.
• Mixed (complex) sleep apnea — a combination of obstructive and central events, sometimes emerging on CPAP therapy.

This guide focuses primarily on obstructive sleep apnea, which is what most adults who snore loudly will be assessed for.

Symptoms checklist

The hallmark symptom — witnessed breathing pauses — usually comes from a partner. The list below covers what to ask both yourself and the person you sleep next to:

• Loud snoring most nights (often louder than 60–70 dB)
• Witnessed breathing pauses, gasping, or choking during sleep
• Waking with a dry mouth or sore throat
• Morning headaches that ease over the first hour after waking
• Waking to urinate more than once a night (nocturia)
• Excessive daytime sleepiness, especially in passive situations
• Difficulty concentrating, mood changes, irritability
• Falling asleep at the wheel or in conversation
• High blood pressure that's hard to control
• Reduced libido and erectile dysfunction

Risk factors

• Excess weight — the single strongest risk factor.
• Large neck circumference — above 16.5 inches (men) or 16 inches (women).
• Male sex — men are 2–3× more likely to have OSA than pre-menopausal women.
• Age — risk rises from middle age onward.
• Family history — anatomical features are heritable.
• Alcohol, sedatives, and smoking — all worsen airway collapse.
• Anatomical factors — recessed jaw, large tonsils, deviated septum, long soft palate.
• Menopause — sharply increases risk in women.
• Medical conditions — hypothyroidism, type 2 diabetes, heart failure, PCOS.

AHI severity scale

The Apnea–Hypopnea Index (AHI) is the number of breathing pauses (apneas) and shallow-breathing events (hypopneas) per hour of sleep, measured during a sleep study. It's the primary way severity is graded:

Snoring vs sleep apnea: how to tell them apart

Most snorers do not have sleep apnea, but most people with sleep apnea snore loudly. The distinguishing features:

• Snoring is continuous noise during inhalation, often steady.
• Apnea features repeated pauses of silence, ending with a gasp, choke, or loud snort.
• People with apnea wake unrefreshed regardless of total hours slept.
• Morning headaches and excessive daytime sleepiness are far more typical of apnea than plain snoring.

See the full side-by-side comparison in snoring vs sleep apnea.

How sleep apnea is diagnosed

Diagnosis follows a clear three-step pathway in the UK:

1. GP consultation. Your GP will ask about symptoms, examine your airway and BMI, and often use a screening questionnaire such as STOP-BANG or the Epworth Sleepiness Scale.
2. Home sleep test. Most adults are now referred for a home study first — a small device that records breathing, blood oxygen, and heart rate overnight in your own bed.
3. In-clinic polysomnography — used if home results are inconclusive or if central or complex apnea is suspected. Adds brain wave (EEG), eye movement, and muscle activity recording.

Read our full sleep study guide for what to expect on the night.

When to ask your GP for a sleep study

Book a GP appointment and specifically ask about a sleep study if any of the following apply:

• Your partner has witnessed breathing pauses, gasping, or choking
• You snore loudly almost every night
• You wake unrefreshed regardless of hours slept
• You have morning headaches
• You feel sleepy during the day or have fallen asleep at the wheel
• You have high blood pressure that's hard to control
• You have type 2 diabetes, atrial fibrillation, or have had a stroke

Treatment options

1. Lifestyle changes

Weight loss is the single most effective intervention for overweight patients with mild-to-moderate OSA — a 10% reduction in body weight typically reduces AHI by around 25%. Cutting alcohol, quitting smoking, and side sleeping all help. See how to stop snoring for the full programme.

2. CPAP therapy (gold standard)

Continuous Positive Airway Pressure (CPAP) delivers pressurised air through a mask to splint the airway open. It is the first-line treatment for moderate and severe apnea and effectively eliminates events when worn consistently. The main challenge is tolerance — around a third of patients struggle with the mask.

3. Oral appliances (MADs)

Custom-fitted mandibular advancement devices reposition the lower jaw forward, opening the airway. NICE recommends MADs as first-line for mild OSA and as an alternative for moderate cases when CPAP isn't tolerated. See our anti-snoring devices hub.

4. Positional therapy

For patients whose apnea only occurs when lying on the back, side-sleeping devices (positional belts, body pillows) can be sufficient on their own.

5. Surgery

Reserved for clear anatomical causes: septoplasty for a deviated septum, tonsillectomy for enlarged tonsils, or uvulopalatopharyngoplasty (UPPP) for redundant soft-palate tissue. Maxillomandibular advancement is the most effective surgical option for severe OSA but is reserved for selected patients.

6. Hypoglossal nerve stimulation

A newer implanted device (Inspire) that stimulates the tongue nerve during sleep. Available in selected UK centres for moderate-to-severe OSA when CPAP isn't tolerated.

If CPAP doesn't work for you

Around a third of CPAP users discontinue therapy within a year due to mask discomfort, claustrophobia, or air-pressure intolerance. Don't give up on treatment — there are robust alternatives. We cover them in detail in our CPAP alternatives guide.

Risks of leaving sleep apnea untreated

Untreated moderate-to-severe sleep apnea is associated with significantly elevated risk of:

• High blood pressure (often treatment-resistant)
• Heart attack and coronary artery disease
• Stroke
• Atrial fibrillation and other arrhythmias
• Type 2 diabetes
• Depression and cognitive impairment
• Road traffic accidents from daytime sleepiness

See our deep-dive on the risks of untreated snoring and apnea.

Living with sleep apnea

Sleep apnea is a chronic condition rather than something that's permanently cured, but it is highly treatable. Most patients on consistent CPAP or a well-fitted oral appliance report dramatic improvements in energy, mood, and cardiovascular markers within weeks. Combine treatment with weight management, regular exercise, alcohol moderation, and good sleep hygiene for the best long-term outcome.

If you're newly diagnosed, also read our overview of snoring causes and treatments and the relationship impact guide — both apnea-relevant.