1. Heart conditions
Heart attacks or arrhythmias (irregular heartbeats) are common causes. Sometimes, a person may experience a sudden fatal heart arrhythmia like ventricular fibrillation, which disrupts the heart’s normal rhythm, leading to a loss of heart function and death.
2. Sudden Cardiac Arrest (SCA)
This happens when the heart unexpectedly stops pumping blood due to electrical disturbances. People with underlying heart disease or those who experience an undiagnosed heart condition are at greater risk.
Obstructive sleep apnea can cause intermittent stopping of breathing during sleep. Severe cases may increase the risk of sudden cardiac death, especially in individuals with other cardiovascular problems.
4. Stroke
A stroke can also occur during sleep, particularly in individuals who have high blood pressure, are smokers, or have other risk factors for cerebrovascular events.
5. Respiratory issues
Conditions like chronic obstructive pulmonary disease (COPD) or severe asthma can lead to respiratory failure, especially at night when the body is more relaxed, making it harder to breathe properly.
6. Diabetes
People with poorly managed diabetes may experience complications like diabetic ketoacidosis or hypoglycemia (low blood sugar) during sleep, which can lead to death if not addressed.
7. Severe infections
Sepsis or infections that affect the heart (such as endocarditis) can also cause sudden death, especially in individuals with weakened immune systems.
8. Epilepsy
People with seizure disorders (epilepsy) may experience sudden unexpected death in epilepsy (SUDEP), which can happen during sleep, though the exact cause is not entirely understood.
9. Age and frailty
Older adults, especially those who are frail or suffering from multiple health problems, may pass away in their sleep due to their body’s inability to cope with various medical conditions.
10. Drug overdose
Overdose of certain medications or recreational drugs can cause death in sleep, particularly opioids, which slow down breathing and heart rate.
In some cases, no specific cause is identified even after autopsy, and people die unexpectedly due to natural causes or undiagnosed conditions.