Sleep Apnea 101

Symptoms of Complex Sleep Apnea

Complex Sleep Apnea, also known as Treatment-Emergent Central Sleep Apnea (TECSA), is a sophisticated and multifaceted sleep disorder that emerges when a patient with obstructive sleep apnea (OSA) develops central sleep apnea (CSA) after initiating positive airway pressure (PAP) therapy. This condition combines features of both obstructive and central sleep apneas, making it challenging to diagnose and manage. Understanding the symptoms of complex sleep apnea is crucial for timely diagnosis and effective treatment. This article explores the various symptoms associated with complex sleep apnea, shedding light on its impact on patients’ health and quality of life.

Understanding Complex Sleep Apnea

Illustrations showing difference between normal breathing and obstructive sleep apnea

Before delving into the symptoms, it is essential to understand the nature of complex sleep apnea. Obstructive sleep apnea is characterized by repeated episodes of partial or complete obstruction of the upper airway during sleep, leading to breathing pauses and a reduction in blood oxygen levels. Central sleep apnea, on the other hand, occurs when the brain fails to send appropriate signals to the muscles that control breathing. Complex sleep apnea involves a combination of these two types, where central apneas appear or persist despite the use of PAP therapy for obstructive apneas.

Primary Symptoms of Complex Sleep Apnea

Frequent Awakenings and Fragmented Sleep

One of the hallmark symptoms of complex sleep apnea is frequent awakenings during the night. Patients often experience a sensation of choking, gasping, or shortness of breath, which disrupts their sleep and leads to fragmented sleep patterns. These awakenings are typically associated with the transition between different types of apnea.

Loud Snoring

Loud and chronic snoring is a common symptom of obstructive sleep apnea and can persist in complex sleep apnea. Snoring is caused by the vibration of soft tissues in the throat due to partial airway obstruction and can be disruptive not only to the patient but also to their bed partner.

Gasping or Choking Sensations

Patients with complex sleep apnea may frequently wake up with a sensation of gasping or choking. This occurs due to the abrupt cessation of breathing during central apnea episodes, which can be alarming and distressing.

Daytime Symptoms

Bored tired businesswoman yawning at workplace

Excessive Daytime Sleepiness (EDS)

Excessive daytime sleepiness is a prevalent symptom of complex sleep apnea. Due to the frequent disruptions in sleep, patients often struggle to stay awake and alert during the day. This can lead to difficulties in concentration, memory problems, and an increased risk of accidents.

Fatigue and Lack of Energy

Chronic fatigue and a general lack of energy are common in individuals with complex sleep apnea. Repeated interruptions in sleep prevent the body from achieving restorative sleep, leading to persistent tiredness and decreased physical and mental performance.

Morning Headaches

Morning headaches are often reported by patients with complex sleep apnea. These headaches are typically caused by fluctuations in oxygen levels during sleep and the resultant strain on blood vessels and muscles in the head and neck.

Cognitive Impairment

Complex sleep apnea can lead to cognitive impairments, including difficulties with attention, memory, and executive function. These cognitive deficits are likely due to the chronic sleep deprivation and intermittent hypoxia experienced by patients.

Cardiovascular and Metabolic Symptoms


Hypertension, or high blood pressure, is commonly associated with complex sleep apnea. The repeated episodes of oxygen desaturation and arousal from sleep can trigger the release of stress hormones, leading to elevated blood pressure.


Cardiac arrhythmias, or irregular heartbeats, are also linked to complex sleep apnea. The stress on the cardiovascular system from fluctuating oxygen levels and repeated arousals can lead to abnormal heart rhythms, increasing the risk of heart disease.

Insulin Resistance

Complex sleep apnea has been associated with metabolic disturbances, including insulin resistance. Chronic sleep fragmentation and hypoxia can disrupt glucose metabolism and insulin sensitivity, increasing the risk of developing type 2 diabetes.

Psychological Symptoms

Depression and Anxiety

Depression and anxiety are commonly observed in patients with complex sleep apnea. The chronic sleep disturbances and the associated physical and cognitive symptoms can significantly impact mental health, leading to mood disorders.

Irritability and Mood Swings

Patients with complex sleep apnea may experience irritability and frequent mood swings. The constant fatigue and sleep deprivation can affect emotional regulation, leading to increased irritability and emotional instability.

Complications and Health Risks

Young woman suffering from chest pain

Increased Risk of Cardiovascular Disease

The combination of obstructive and central sleep apnea in complex sleep apnea significantly increases the risk of cardiovascular disease. This includes conditions such as hypertension, coronary artery disease, heart failure, and stroke.

Impaired Immune Function

Chronic sleep disruption and the stress response associated with complex sleep apnea can impair immune function, making patients more susceptible to infections and other health issues.

Impact on Quality of Life

The multitude of symptoms associated with complex sleep apnea can severely impact a patient’s quality of life. Persistent fatigue, cognitive impairments, mood disturbances, and physical health issues can interfere with daily activities, work performance, and social interactions.

Diagnosis and Treatment

Polysomnography (Sleep Study)

The diagnosis of complex sleep apnea typically involves a comprehensive sleep study, known as polysomnography. This test records various physiological parameters during sleep, including brain activity, eye movements, muscle activity, heart rate, and respiratory function. Polysomnography can help differentiate between obstructive and central apneas and assess the severity of the condition.

Positive Airway Pressure (PAP) Therapy

Positive airway pressure (PAP) therapy is the primary treatment for obstructive sleep apnea and is also used in the management of complex sleep apnea. However, the presence of central apneas may necessitate adjustments to the therapy. Adaptive servo-ventilation (ASV) is a specialized form of PAP therapy that can be effective in treating complex sleep apnea by automatically adjusting pressure levels to stabilize breathing patterns.

Lifestyle Modifications

Lifestyle modifications can play a supportive role in managing complex sleep apnea. These include maintaining a healthy weight, avoiding alcohol and sedatives, quitting smoking, and adopting good sleep hygiene practices. Weight loss, in particular, can reduce the severity of obstructive apneas and improve overall sleep quality.

Medical and Surgical Interventions

In some cases, medical or surgical interventions may be necessary to address underlying conditions contributing to complex sleep apnea. These can include treating nasal obstructions, removing enlarged tonsils, or addressing other anatomical abnormalities.


Complex sleep apnea is a multifaceted condition that combines the characteristics of obstructive and central sleep apnea. Its symptoms can significantly impact a patient’s physical, cognitive, and emotional well-being, underscoring the importance of timely diagnosis and effective treatment. Understanding the symptoms of complex sleep apnea is crucial for healthcare providers and patients alike, as it enables prompt intervention and the implementation of appropriate management strategies. With proper treatment and lifestyle adjustments, individuals with complex sleep apnea can improve their sleep quality, overall health, and quality of life.

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