Why do peoplpe die in their sleep?
Death during sleep is something that can catch people off guard, leaving loved ones with more questions than answers. While sleep is usually a time for rest, for some, it can become the time when life ends unexpectedly. The causes behind such deaths are usually different heart problems, strokes, and sleep disorders like sleep apnea, to name a few examples.
Often, these events occur without any clear warning, making them hard to predict or prevent. In this blog, we’ll explore the reasons why people sometimes die in their sleep, looking at the health conditions and risk factors that contribute to these incidents and how we can reduce the chances through awareness and lifestyle changes.
Heart conditions
Several heart conditions can contribute to death during sleep, often in connection with sleep disorders that either worsen existing heart problems or help trigger new ones.
Sleep apnea: One such condition is sleep apnea, which causes pauses in breathing or shallow breathing during sleep. This disorder can lead to serious complications like high blood pressure, stroke, sudden cardiac death, asthma, COPD, and diabetes mellitus [1].
Obstructive sleep apnea, in particular, has been linked to a higher risk of sudden death from cardiac causes during sleep [2].
Cheyne-Stokes respiration: Another sleep-related condition, Cheyne-Stokes respiration (CSR), is commonly seen in patients with chronic heart failure. CSR increases sympathetic nervous activity and disrupts sleep quality, potentially triggering cardiac events during sleep [3].
Chronic insomnia: Chronic insomnia, which is characterised by difficulty falling or staying asleep for at least 3 nights a week over a span of 3 months, has been linked to high blood pressure and heart disease [4].
Other sleep-related disorders: Other sleep disorders, like narcolepsy and restless legs syndrome (RLS), can also impact heart health. Narcolepsy and its treatments may raise blood pressure and contribute to other risk factors for heart disease. RLS, especially when untreated, is associated with a higher cardiovascular risk [4].
Respiratory conditions
Sleep Apnea: Sleep apnea is a common but serious condition where people struggle to breathe or even stop breathing for short periods while sleeping. It often goes undiagnosed, but it can lead to or worsen several life-threatening issues like high blood pressure, stroke, sudden cardiac death, asthma, COPD, and diabetes mellitus [1].
In a few cases, sleep-induced apnea can cause sudden, unexplained death, with symptoms like confusion, fatigue, and weakness often leading up to it. This condition is also characterised by low blood pressure, slow heart rate, low sodium levels, hypothermia, hormone imbalances, and difficulty urinating [5].
Familial dysautonomia: Sudden unexpected death during sleep (SUDS) is a common cause of death in individuals with familial dysautonomia (FD), a condition that is characterised by sensory and autonomic dysfunction. SUDS in FD is often linked to sleep-related breathing disorders [6].
Nocturnal Hypoxia: Sleep-related breathing issues may play a role in the higher mortality rate at night. Nocturnal hypoxia, or low oxygen levels during sleep, has been associated with serious heart issues, including ventricular tachyarrhythmias and life-threatening bradyarrhythmias [7].
COPD: Patients with chronic obstructive pulmonary disease (COPD) often suffer from sleep-related breathing disorders (SRBDs), which can significantly increase their risk of complications and death if not properly diagnosed and treated [8].
Hypoxemia: Those with hypoxemia due to respiratory conditions may experience further oxygen desaturation during sleep, resulting in nocturnal hypoxemia. This is especially common in patients with scoliosis [9].
MSA-AF: Multiple system atrophy with autonomic failure (MSA-AF) can lead to serious breathing problems, especially during sleep, due to upper airway dysfunction and disrupted breathing patterns. Even mild sleep-related breathing issues in these patients may require a tracheostomy for safety [10, 11].
Chronic lung conditions: Sleep has a major impact on breathing, and for people with chronic lung conditions, this can make things worse—especially if they're already dealing with low oxygen levels. Sleep-related breathing issues can trigger heart problems, like arrhythmias and pulmonary hypertension, and increase the risk of dying in their sleep, particularly during flare-ups of their condition [12].
The Impact of Alcohol and Drug Use on Sleep-Related Deaths
Alcohol and drug use can have a serious impact on sleep, often leading to various disturbances that raise the risk of health issues. While alcohol is often used as a sleep aid because of its initial sedative effects, it actually disrupts the sleep cycle. It can cause insomnia, interfere with circadian rhythms, and reduce sleep duration. Alcohol also exacerbates breathing problems during sleep, such as snoring and oxygen desaturation, especially in people with pre-existing sleep conditions.
In conclusion, alcohol and drug use can lead to serious sleep disturbances that not only harm overall health but also increase the risk of various conditions and potentially contribute to a higher risk of mortality.
Other conditions that can cause death in sleep
A less common but very serious cause is dead-in-bed syndrome (DBS), which mainly affects young people with type 1 diabetes. DBS is linked to episodes of low blood sugar that interfere with the brain’s ability to wake up properly, affecting the muscles that keep the airway open. This can lead to sudden heart and respiratory failure during sleep [13].
Sudden infant death syndrome (SIDS) is a leading cause of death in infants under 1 year old. Though the exact cause remains unknown, it's thought that a combination of physical and environmental sleep factors can make an infant more vulnerable to SIDS [14].
Lastly, certain sleep disorders can lead to dangerous or even fatal outcomes. Complex behaviours that occur during sleep, such as sleepwalking or night terrors, may result in violent actions or
injuries. In some cases, these incidents can be mistaken for suicides, even though they are sleep-related [15].