Sleep apnea

Sleep apnea is a sleep disorder in which breathing repeatedly stops and starts. If you snore loudly and feel tired even after a full night's sleep, you might have sleep apnea.

The main types of sleep apnea are:

• Obstructive sleep apnea (OSA), is the more common form caused by throat muscle relaxation and anatomical features.
• Central sleep apnea (CSA), occurs when the brain doesn't send proper signals to the muscles that control breathing.

If you think you might have sleep apnea, see your doctor. Treatment can ease your symptoms and might help prevent heart problems and other complications.

Symptoms

The symptoms of obstructive and central sleep apneas overlap, sometimes making it difficult to determine which type you have. The most common symptoms of obstructive and central sleep apneas include:

• Loud snoring;
• Episodes in which you stop breathing during sleep — which would be reported by another person;
• Gasping for air during sleep;
• Awakening with a dry mouth;
• Morning headache;
• Difficulty staying asleep, known as insomnia;
• Excessive daytime sleepiness, known as hypersomnia;
• Difficulty paying attention while awake;
• Irritability.

When to see a doctor

Loud snoring can indicate a potentially serious problem, but not everyone who has sleep apnea snores. Talk to your doctor if you have symptoms of sleep apnea. Ask your doctor about any sleep problem that leaves you fatigued, sleepy and irritable.

Causes

Obstructive sleep apnea

This type of sleep apnea happens when the muscles in the back of the throat relax. These muscles support the soft palate, the triangular piece of tissue hanging from the soft palate called the uvula, the tonsils, the side walls of the throat and the tongue.

When the muscles relax, the airway narrows or closes as you breathe in. You can't get enough air, which can lower the oxygen level in your blood. Your brain senses that you can’t breathe, and briefly wakes you so that you can reopen your airway. This awakening is usually so brief that you don’t remember it. You might snort, choke or gasp. This pattern can repeat 5 to 30 times or more each hour, all night. This disrupts phases of sleep.

Central sleep apnea

Central sleep apnea is less common form of sleep apnea and it occurs when your brain fails to send signals to your breathing muscles.   Accordingly, breathing stops for a short period.

Risk factors

Sleep apnea can affect anyone, including children. But certain factors increase the risk of disease development.                                 

Obstructive sleep apnea                                       

The   sleep apnea may be caused by the following factors:

• Excess weight. Obesity greatly increases the risk of OSA. Fat deposits around the upper airway obstruct your breathing.
• Neck circumference. People with thicker necks might have narrower airways.
• A narrowed airway. You might have inherited a narrow throat. Tonsils or adenoids also can enlarge and block the airway. This happens often particularly in children.
• Male. Men are 2 to 3 times more likely to have sleep apnea than women. However, the risk of disease in women increase, if they're overweight or have reached menopause.
• Older age. The risk of developing apnea also increases with age.
• Family history.  A family history of sleep apnea might increase your risk.
• Use of alcohol, sedatives or tranquillizers. Alcohol, sedatives or tranquillizers relax muscles in your throat, which can worsen obstructive sleep apnea.
• Smoking. Smokers are three times more likely to suffer from obstructive sleep apnea than non-smokers. Smoking can lead to inflammation and fluid retention in the upper airways.
• Nasal congestion. Any problems with breathing through your nose — whether it is caused by anatomical reasons or allergies — increase the risk of developing obstructive sleep apnea.
• Other diseases. Congestive heart failure, high blood pressure and type 2 diabetes are some of the conditions that may increase the risk of obstructive sleep apnea. Polycystic ovary syndrome, hormonal disorders, prior stroke and chronic lung diseases such as asthma, can also increase risk.

Central sleep apnea                                 

Risk factors for this form of sleep apnea include:

•  Middle-aged and older people have a higher risk of central sleep apnea.
• Male. Central sleep apnea is more common in men than it is in women.
• Heart disorders.   Congestive heart failure increases the risk.
• Using narcotic pain medicines. Medicines, especially long-acting effects, increase the risk of central sleep apnea.
• Stroke. A stroke increases the risk of central sleep apnea.

Complications                                 

Sleep apnea is a serious medical condition that may have the following complications:

The repeated awakenings associated with sleep apnea make restorative sleep impossible, which in turn results in severe daytime drowsiness, fatigue and irritability.

You may experience difficulties with concentration, and you may suddenly fall asleep at work, while watching TV, or while driving. People with sleep apnea are at a higher risk of vehicle or industrial accidents.

You may experience shortness of breath, sudden mood change, or depression. Children and adolescents with sleep apnea may have learning or behavior problems.

• High blood pressure or heart problems. Sudden drops in blood oxygen levels that occur during OSA increase blood pressure and strain the cardiovascular system. Having OSA increases your risk of high blood pressure, also known as hypertension. OSA might also increase your risk of recurrent heart attack, stroke and irregular heartbeats, such as atrial fibrillation.
• Type 2 diabetes. Having sleep apnea increases your risk of developing insulin resistance and type 2 diabetes.
• Metabolic syndrome. This disorder includes high blood pressure, abnormal cholesterol levels, high blood sugar and an increased waist circumference, which is associated with a higher risk of heart disease.
• Complications with medicines and surgery. Obstructive sleep apnea is also a concern with certain medicines and general anesthesia.  
• Liver problems. Those who suffer from sleep apnea often have liver dysfunction, as well as non-alcoholic fatty liver disease caused by non-alcoholic factors.
• Inability to sleep. Loud snoring can disrupt others’ sleep. Another person usually goes to another room or floor to be able to sleep.

Sleep apnea also occurs in children!

The American Academy of Pediatrics recommends evaluating sleep apnea in any child who snores more than three nights a week! The prevalence of sleep apnea among the pediatric population is 1-5 percent.

Risk factors for developing sleep apnea in children include:

• Adenotonsillar hypertrophy;
• Excess weight;
• Orthodontic problems;
• Cerebral palsy;
• Down syndrome;
• Muscular dystrophy and other neuromuscular disorders;
• Other genetic syndromes.

Symptoms of sleep apnea in children:

• Snoring;
• Daytime drowsiness at school.

The  sleep apnea in children can lead to the following complications:

• Studying problems;
• Behavioral disorders;
• Enuresis.

Long-term complications:

• Growth delay;
• Cardiovascular diseases.

Overnight sleep study is conducted using a polysomnography. Polysomnography is an objective method for diagnosing sleep apnea.

Polysomnography, also known as a sleep study, is a test used to diagnose sleep disorders. Polysomnography records brain waves, the oxygen levels in blood, heart rate, and breathing during sleep. It also measures eye and leg movements.

Polysomnography studies the following parameters:

• Respiratory effort and airflow;
•  Oxygen saturation;
• Heart rate and rhythm;
• Duration of sleep stages;
• Body position;
• Muscle activity;
• Oculography;
• Electroencephalographic channels;
• Video telemetry.