Introduction
What is sleep apnea?
Sleep apnea is when breathing stops and starts repeatedly during sleep. It can cause interruptions in sleep, making people feel tired during the day. Also, these interruptions in breathing lower sleep quality. Untreated sleep apnea results in serious health issues.1 The two main types of sleep apnea are:
- Obstructive Sleep Apnea (OSA) is the most common type of sleep apnea. It happens when the muscles in the throat relax too much during sleep, which blocks the airway. This blockage makes it hard to breathe, causing the person to wake up frequently to reopen the airway.1
- Central Sleep Apnea (CSA): This less common type happens when the brain fails to send proper signals to the muscles that control breathing. CSA occurs due to a problem in the communication between the brain and the muscles that help in breathing.1
What is a stroke?
A stroke is a severe medical condition that happens when blood flow to a part of the brain is blocked or interrupted. Brain cells get affected in the absence of adequate blood supply.2 There are mainly two types of strokes:
- Ischemic stroke: This is the most common type of stroke. It happens when a blood vessel that supplies blood to the brain gets blocked by a blood clot. This blockage prevents blood and oxygen from reaching parts of the brain.2
- Haemorrhagic stroke: This type of stroke happens when a blood vessel in the brain ruptures, leading to bleeding inside or around the brain. This bleeding increases pressure on brain cells, causing damage.2
Understanding the link between sleep apnea and stroke is important because people with sleep apnea are at a higher risk of having a stroke. Knowing this connection can help one take steps to reduce this risk. Early diagnosis and treatment of sleep apnea can potentially prevent strokes and improve overall health.
Understanding sleep apnea
Sleep apnea can happen for different reasons:
- During sleep, the muscles in the throat relax too much.The airway becomes constricted or blocked, making breathing difficult. It is the primary cause of Obstructive Sleep Apnea (OSA).
- When the brain does not send the right signals to the muscles that control breathing it means the person makes no effort to breathe for short periods. This cause is associated with Central Sleep Apnea (CSA).
Symptoms
Sleep apnea can have several noticeable symptoms:
- Loud snoring: One of the most common signs of sleep apnea is loud and chronic snoring. The snoring usually happens because of the partial blockage of the airway.1
- Pauses in breathing during sleep: Another significant symptom is noticeable pauses in breathing during sleep. These pauses can last from a few seconds to a minute and may occur many times during the night. It is observed by a partner.1
- Feeling very tired during the day: People with sleep apnea often feel very tired and sleepy during the day, despite the night sleep. This daytime fatigue is due to the poor quality of sleep caused by frequent interruptions in breathing.1
- Dry mouth upon waking up1
How is it diagnosed?
Doctors use a couple of methods to diagnose sleep apnea:
- The most reliable way to diagnose sleep apnea is with an overnight sleep test called a polysomnography. During this test, you stay overnight at a sleep center. The test monitors various body functions like brain activity, eye movement, muscle activity, heart rhythm, and breathing patterns while you sleep.3
- Sometimes, doctors may recommend a home sleep test. It is a simple test that you can do in your own home. It involves wearing a few sensors that measure your breathing patterns, oxygen levels, and heart rate while you sleep. The results can help doctors determine if you have sleep apnea.3
Understanding stroke
A stroke occurs when blood flow to the brain is blocked. The two causes are ischemic and haemorrhagic stroke
Symptoms
Stroke symptoms can be sudden and noticeable as:
- You might suddenly feel weak or numb in your face, arm, or leg, especially on one side of your body.2
- You may have trouble speaking clearly or understanding what others are saying. You may slur your words or find it hard to talk.2
- You might suddenly have blurry vision or even lose vision in one or both eyes. You could also get a sudden, severe headache with no obvious cause.2
How is it diagnosed?
Doctors use a few methods to diagnose a stroke:
- Physical and neurological exams: The doctor will examine and ask questions about your symptoms and medical history. They check your reflexes, strength, and coordination.4
- Brain scans (CT or MRI): These special tests create detailed images of your brain. CT scan uses X-rays to take pictures while MRI uses magnets and radio waves. These scans help doctors find if there’s bleeding or if part of the brain has insufficient blood supply.4
How are sleep apnea and stroke linked?
Sleep apnea and stroke are connected through several mechanisms. During episodes of sleep apnea, where breathing stops and starts. The body experiences a drop in oxygen levels and fluctuations in blood pressure. These conditions stress the cardiovascular system, leading to inflammation and endothelial dysfunction (problems with the lining of blood vessels).5
Over time, these effects cause worsening conditions like high blood pressure, atherosclerosis (hardening of the arteries), and cardiac arrhythmias (irregular heartbeats). These cardiovascular problems are significant risk factors for stroke.
Research has shown that people with untreated sleep apnea have a higher risk of experiencing a transient ischemic attack (TIA) or stroke compared to those without sleep apnea. The interrupted breathing and oxygen deprivation during sleep can trigger processes that promote the formation of blood clots or plaque buildup in the arteries increasing the likelihood of a stroke.5
Management and treatment
Managing and treating sleep apnea is crucial for improving sleep quality and overall health and reducing the risk of stroke. This involves interventions like continuous positive airway pressure (CPAP) therapy and lifestyle changes such as avoiding smoking and alcohol consumption. Sometimes surgical procedures are required to keep the airway open during sleep, thus lowering the risks associated with sleep apnea-related cardiovascular complications, including stroke.5
FAQs
What is sleep apnea?
In sleep apnea, breathing repeatedly stops and starts during sleep. This can cause poor sleep quality and lead to serious health problems if untreated.
How does sleep apnea increase the risk of stroke?
Sleep apnea can lead to low oxygen levels and sudden changes in blood pressure during sleep. These effects strain the cardiovascular system, causing inflammation and damage to blood vessels, which can increase the risk of stroke.
What are the symptoms of sleep apnea?
Common symptoms include loud snoring, pauses in breathing during sleep, and tiredness despite night sleep.
How can I tell if someone has sleep apnea?
Signs to watch for include loud snoring, choking or gasping during sleep, frequent awakenings, and excessive daytime sleepiness. A doctor diagnoses sleep apnea through a sleep study.
What is a stroke?
A stroke happens when blood flow to a part of the brain is blocked or when a blood vessel in the brain bursts, leading to brain damage. Symptoms include sudden weakness, trouble speaking, and severe headache.
How is sleep apnea treated?
Treatments include using a CPAP machine to keep the airway open during sleep, lifestyle changes like losing weight and avoiding smoking, alcohol, oral appliances, and sometimes surgery.
How can treating sleep apnea reduce stroke risk?
Blood pressure reduces strain on the heart and blood vessels. It lowers the risk of stroke and other cardiovascular problems.
Is there a connection between sleep apnea and other health problems?
Yes, sleep apnea causes several other health issues, including high blood pressure, heart disease, diabetes, and stroke. Treating sleep apnea can improve overall health and reduce the risk of these conditions.
Summary
Sleep apnea is when breathing stops and starts during sleep. This can lead to serious health problems if not treated. There are two main types: obstructive sleep apnea (OSA), which happens when the airway is blocked, and central sleep apnea (CSA), when the brain stops sending the right signals to breathe.
A stroke happens when the brain doesn't get enough blood, causing damage. There are two types: ischemic (blocked blood flow) and hemorrhagic (bleeding in the brain).
Sleep apnea increases the risk of stroke because it causes low oxygen levels and sudden changes in blood pressure during sleep, which puts stress on the heart and blood vessels.
Treating sleep apnea with CPAP machines, lifestyle changes like losing weight and avoiding smoking, alcohol and sometimes surgery can lower this risk. Managing sleep apnea is crucial for better sleep, overall health, and reducing the risk of stroke. Regular doctor visits and sticking to treatment are necessary for effective management.
References
- Sleep apnea. Sleep Foundation [Internet]. 2020 [cited 2024 Jun 14]. Available from: https://www.sleepfoundation.org/sleep-apnea.
- Stroke - Symptoms and causes. Mayo Clinic [Internet]. [cited 2024 Jun 14]. Available from: https://www.mayoclinic.org/diseases-conditions/stroke/symptoms-causes/syc-20350113.
- Selim BJ, Koo BB, Qin L, Jeon S, Won C, Redeker NS, et al. The Association between Nocturnal Cardiac Arrhythmias and Sleep-Disordered Breathing: The DREAM Study. Journal of Clinical Sleep Medicine [Internet]. 2016 [cited 2024 Jun 14]; 12(06):829–37. Available from: http://jcsm.aasm.org/doi/10.5664/jcsm.5880.
- Stroke - Diagnosis. nhs.uk [Internet]. 2017 [cited 2024 Jun 14]. Available from: https://www.nhs.uk/conditions/stroke/diagnosis/.
- Jehan S, Farag M, Zizi F, Pandi-Perumal SR, Chung A, Truong A, et al. Obstructive sleep apnea and stroke. Sleep Med Disord [Internet]. 2018 [cited 2024 Jun 14]; 2(5):120–5. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6340906/.