People with obstructive sleep apnea (OSA) usually have low oxygen levels during sleep because of gaps in their breathing. If your blood oxygen level is less than 95% while you sleep, your blood oxygen level is considered low. If it is below 92%, medical intervention may be recommended.
Low blood oxygen can lead to the following risks: hypoxemia Your tissues don’t get the oxygen they need to function, causing fatigue, lightheadedness, and shortness of breath. Over time, the hypoxia associated with OSA can increase the risk of stroke and brain aneurysm, and even affect cognitive function.
This article explains what sleep apnea is and how it affects blood oxygen levels. We also discuss the causes, symptoms, and diagnosis of obstructive sleep apnea, and explore other possible causes of low blood oxygen levels during sleep.
What is obstructive sleep apnea?
Obstructive sleep apnea is one of the two main forms of sleep apnea, where the muscles in your throat relax and block the passage of air into your body. trachea (Trachea) While sleeping. When this happens, some people may stop breathing for a few seconds to more than a minute.
People with OSA have frequent breathing gaps, with some experiencing more than 100 breathing gaps per night. OSA patients may not be aware of these gaps, but their sleep partners often are.
According to the National Council on Aging, approximately 39 million adults in the United States have sleep apnea, and 33 million of them use a CPAP machine to normalize their breathing at night.
Sleep apnea and normal blood oxygen levels
Obstructive sleep apnea can affect blood oxygen levels due to insufficient air intake during sleep.
During the day, blood oxygen levels (also called oxygen saturation levels) typically fall between 95% and 100% in healthy people, whether they are asleep or awake. This is considered normal.
However, prolonged or repeated breathing gaps during sleep can reduce oxygen levels and harm tissues and organs. This is called sleep-related hypoxemia.
Oxygen saturation below 92% usually requires medical intervention. This is a level commonly seen in COPD patients receiving oxygen therapy.
The interpretation of oxygen saturation level can be explained as follows.
Interpretation of Oxygen Saturation 95% to 100% Normal 93% to 94% Borderline Low 89% to 92% Low. Continue to monitor and contact your health care provider. Below 88% Dangerously low. Seek medical attention immediately
Symptoms of sleep apnea syndrome
Sleep apnea is often recognized by your sleep partner, but if you live alone or sleep alone, you should be aware of the following signs and symptoms of OSA: .
When sleep-related hypoxemia occurs, more serious and problematic symptoms can occur, including:
Anxiety when waking up Shortness of breath Palpitations Dizziness or lightheadedness
cyanosis (Skin discoloration due to lack of oxygen)
tinnitus (My ears are ringing)
Of further concern is that sleep-related hypoxemia can cause peripheral venodilation (which refers to swelling of the veins, usually caused by a spike in blood pressure). OSA can cause cerebrovascular diseases such as: ischemic strokecerebral aneurysm, cerebral hemorrhage, carotid artery disease.
Risk factors for obstructive sleep apnea syndrome
People of all ages, genders, and weights can develop obstructive sleep apnea, but it is more common in men, people over 50, and people diagnosed with obesity.
Other risk factors for OSA include:
smoking cigarettes sleeping on your back regularly using alcohol or sedatives having enlarged tonsils or adenoids having an underactive thyroid (hypothyroidism) having had a stroke nasal cavity or sinuses, throat, tongue, or other areas anatomical abnormalities of epiglottis
diagnosis
Obstructive sleep apnea is diagnosed through an overnight sleep study. sleep polygram. This is a test performed in a specialized facility that records several physical symptoms during sleep. This includes checking your blood oxygen levels.
The components of an overnight sleep study are:
Electroencephalography (EEG): Measures brain waves during different stages of sleep to identify sleep disorders. Electrocardiogram (EKG): This measures the electrical activity of the heart to check for any problems that may be a cause or result of OSA. Electromyography (EMG): Tracks the movement of your leg muscles and checks for a condition related to OSA called periodic limb movement disorder (PLMD). Electrooculography (EOG): Tracks your eye activity and determines how often you enter rapid eye movement (REM) sleep. Breathing sensor: Measures the movement of air through your mouth and nose, including the breathing gap. Respiratory-guided plethysmography (RIP): This is a belt worn around the torso that measures the expansion of the chest and abdomen during breathing. Pulse oximetry: This is a clamp-like device worn on the tip of the index finger to measure and monitor blood oxygen saturation. Audiovisual monitoring: This allows sleep lab staff to see and record what is happening during your sleep.
Other causes of low blood oxygen levels during sleep
Obstructive sleep apnea is the most common explanation for decreased oxygen saturation during sleep, but it’s not the only one. Other possible causes fall into three broad categories:
Sleep-related hypoventilation: Associated with conditions such as obesity, neuromuscular disorders, lung disease, or neurological disorders that cause hypoventilation (rapid, shallow breathing).
Drug-induced bradypnea: Depnea caused by drugs such as opioids and benzodiazepines. slow breathing (abnormally slow breathing)
Other causes of sleep-related hypoxemia: chronic obstructive pulmonary disease (COPD), heart failure, asthma, pneumonia, nocturnal respiratory allergies, etc.
Treatment of sleep apnea syndrome
Typically, the first-line treatment is continuous positive air pressure (CPAP) therapy. This includes wearing a device that delivers pressurized room air through a mask to keep your airways open at night.
In addition to CPAP, your healthcare provider may recommend:
Sleep positioning devices: Holsters, belts, etc. that prevent you from sleeping on your back Nasal steroids: etc. fluticasone It reduces tissue swelling and keeps the nasal passages open. Adhesive nose strips: These are like breath lights that mechanically widen your nostrils while you sleep. Lose weight: OSA cannot be cured, but it may improve symptoms. Medication: Something like Zepbound (tirzepatide).
In 2024, the FDA approved Zepbound (tirzepatide) for the treatment of moderate to severe OSA in obese adults. Zepbound is the first and only FDA-approved drug to treat OSA.
If these conservative options fail, the following surgeries can relieve airway obstruction and improve airflow from the nose and mouth to the windpipe:
Tonsillectomy or adenoidectomy: Surgery to remove the tonsils or adenoids Uvulopalatopharyngoplasty: Surgery to remove the fleshy part of the soft palate Prognathism: Surgery to move the upper jaw forward
Treating OSA increases blood oxygen levels during sleep. If left untreated, OSA can increase the risk of high blood pressure, coronary artery disease (CAD), atrial fibrillation, and type 2 diabetes. This is why treating OSA is so important, especially in moderate to severe cases.
summary
Obstructive sleep apnea (OSA) is a sleep disorder caused by the muscles in your throat relaxing, which prevents you from breathing. Frequent and long-lasting gaps can reduce oxygen levels in the bloodstream.
Untreated OSA can lead to serious health problems, including increased risk of high blood pressure, heart disease, and diabetes. This is why it’s important to get diagnosed if you have symptoms or risk factors for OSA.
OSA is usually diagnosed with an overnight sleep study that measures blood oxygen with a pulse oximeter. Depending on the results of these and other tests, your doctor will decide which treatment is best for you.