Hypoxia: Causes, Symptoms, Tests, Diagnosis & Treatment (2023)


Hypoxia: Causes, Symptoms, Tests, Diagnosis & Treatment (1)

What is hypoxia?

Hypoxia is when the tissues of your body don’t have enough oxygen. When you breathe, you take oxygen into your lungs, where it travels through your airways out into small sacks called alveoli. From there, it gets picked up by your blood in small vessels that travel close to the alveoli (capillaries). Finally, it travels through your blood out to other tissues.

You can think of oxygen as billions of passengers flying into the airport (your lungs). They get picked up at the gate and get on the highway (blood vessels) to be taken to their destination (your tissues). As the oxygen gets dropped off, it makes room for a different passenger to be picked up: carbon dioxide. Carbon dioxide is a waste product, which is then taken back to your lungs and exits your body when you breathe out.

If not enough oxygen gets through at any place on the journey, it can lead to hypoxia. Airflow and blood flow are both important to the process. This is why lung disease and heart disease both increase your risk of hypoxia. Someone who experiences hypoxia is called hypoxic.

Hypoxia vs. hypoxemia: What’s the difference?

You may hear the words hypoxia and hypoxemia used interchangeably, but they aren’t the same. The names sound similar because they both involve a lack of oxygen but in different parts of your body.

Hypoxia is low oxygen levels in the tissues and hypoxemia is low oxygen levels in the blood. Hypoxia is often caused by hypoxemia but not always. You can be hypoxic but not hypoxemic and vice versa.

Who does hypoxia affect?

Any condition that reduces the amount of oxygen in your blood or restricts blood flow can cause hypoxia. People living with heart or lung diseases such as COPD, emphysema or asthma, are at an increased risk for hypoxia. Some infections, like pneumonia, influenza and COVID-19 can also increase your risk of hypoxia.

(Video) Hypoxia & cellular injury - causes, symptoms, diagnosis, treatment & pathology

What is hypoxia and what does it do to the body?

Your cells need oxygen to produce energy and help your organs and tissues to do their jobs. While some of your tissues can adjust to temporary dips in oxygen levels, prolonged hypoxia can cause organ damage. Brain and heart damage are particularly dangerous and can lead to death. Lack of oxygen to your brain is called cerebral hypoxia.

Symptoms and Causes

What are the signs and symptoms of hypoxia?

Hypoxia symptoms vary depending on the severity, underlying cause and what parts of your body are affected. When your oxygen is low, you might feel like you can’t breathe or think properly. Some hypoxia symptoms include:

  • Restlessness.
  • Headache.
  • Confusion.
  • Anxiety.
  • Rapid heart rate (tachycardia).
  • Rapid breathing (tachypnea).
  • Difficulty breathing or shortness of breath (dyspnea).

Severe hypoxia can cause additional symptoms:

  • Slow heart rate (bradycardia).
  • Extreme restlessness.
  • Bluish skin (cyanosis).

What causes hypoxia?

Hypoxia is most often caused by an underlying illness that affects blood flow or breathing. Conditions that can lead to hypoxia include:

  • Anemia.
  • Asthma.
  • Bronchitis.
  • Chronic obstructive pulmonary disease (COPD).
  • Congenital heart defects.
  • Congestive heart failure.
  • Emphysema.
  • Pneumonia (bacterial and viral).
  • Pneumothorax (air in the space around the lung or collapsed lung).
  • Pulmonary edema (fluid on the lungs).
  • Pulmonary embolism (blood clot in the lung).
  • Pulmonary hypertension.
  • Pulmonary fibrosis (lung scarring).
  • Sleep apnea.

What are the 4 types of hypoxia?

For oxygen to make it to the cells in your tissues, you need:

  • Enough oxygen in the air you breathe in.
  • Healthy lung function to get oxygen to your alveoli.
  • Healthy heart and circulatory functions to get oxygen-rich blood to your tissues.
  • Enough red blood cells to deliver oxygen.
  • Tissue cells capable of using oxygen.

The four types of hypoxia are each caused by a lack of oxygen in any one of these areas.

(Video) Hypoxia: Definition, Causes, Symptoms and Treatment. (What is hypoxia and how dangerous is it?)

Hypoxemic hypoxia

Low amounts of oxygen in the blood (hypoxemia) can lead to hypoxemic hypoxia, the most common cause of hypoxia. Hypoxemia can be caused by lung and heart diseases, congenital heart defects, and medications that slow your breathing. Traveling to a high altitude, where levels of oxygen are lower, can also cause hypoxemia.

Circulatory hypoxia

Your blood can have plenty of oxygen, but not enough of it gets to your tissues if the heart doesn’t pump enough blood or there is a blockage in a blood vessel. This is called circulatory hypoxia (also called stagnant hypoxia or ischemic hypoxia). Congestive heart failure and blood clots can increase your risk of circulatory hypoxia.

Anemic hypoxia

Anemic hypoxia happens when you don’t have enough red blood cells to carry oxygen from your lungs to other tissues. You can become anemic if your body doesn’t make enough red blood cells or it makes deformed red blood cells.

Histotoxic hypoxia

Histotoxic hypoxia happens when your cells aren’t able to use oxygen properly. In this case, you can have plenty of oxygen coming into your lungs and entering your blood. But when it arrives at your tissues, something keeps your cells from being able to use it. This can happen with cyanide poisoning.

Diagnosis and Tests

How is hypoxia diagnosed?

Your healthcare provider will perform a physical exam, including listening to your heart and lungs. They may check your skin, nails and lips to see if they look bluish. Your provider may also order tests to check your oxygen levels and determine the underlying cause of hypoxia, including:

  • Pulse oximetry: Your healthcare provider places a sensor over your finger to measure the amount of oxygen in your blood. This procedure is noninvasive and painless.
  • Arterial blood gas test (ABG): A thin needle is used to draw blood from your wrist, arm, or groin to check your oxygen levels.
  • Pulmonary function test (PFT): You blow out and breathe in to a mouthpiece attached to a machine that measures how well your lungs work.
  • Imaging: X-rays, CT scans, and V/Q scans all use special equipment to get images of your internal organs. Imaging can help your provider determine the cause of hypoxia.
  • Six-minute walk test (6MWT): You walk on a flat surface for six minutes to see how far you can walk in that time. This test helps your healthcare provider evaluate lung and heart function.

Management and Treatment

How is hypoxia treated?

The treatment for hypoxia depends on the underlying cause. The cause might be a one-time event or it could be an ongoing condition. Treatments might include:

  • Inhaled steroids that can open up your airways to treat asthma or other lung disease.
  • Medications that help to reduce excess fluid on the lungs (diuretics).
  • Continuous positive airways pressure mask (CPAP) to treat sleep apnea.
  • BiLevel positive airway pressure (BIPAP) to treat COPD or and some kinds of sleep apnea.
  • Supplemental oxygen to treat ongoing (chronic) hypoxia. An oxygen delivery device is attached to your nose with a mask or tubes to increase the amount of oxygen getting into your lungs and down to your alveoli.
  • Mechanical ventilation in a hospital, in circumstances of severe acute hypoxia (sudden onset).

How do I manage the symptoms of hypoxia?

If you experience symptoms like confusion, rapid heart rate or breathing, or if you notice your nails, lips, or skin appear bluish, you should seek medical attention immediately. Hypoxia should be treated right away to prevent permanent organ damage. COPD and other medical conditions may cause chronic hypoxia with less severe symptoms. Your healthcare provider will talk to you about managing your specific condition to reduce your symptoms and the risk of your oxygen levels dropping too low.

(Video) Hypoxia - Symptoms and Causes. The most common causes of hypoxia


How can I reduce my risk of hypoxia?

The best way to reduce your risk of hypoxia is to manage any underlying conditions that can lower your oxygen levels. If you live with a heart or lung condition, talk to your healthcare provider about your concerns and specific ways to lower your risk. Be aware that certain medications and situations — like traveling to a higher altitude — might increase your risk of hypoxia. Ask your provider about any special precautions you need to take while traveling or changing medication.

Outlook / Prognosis

What can I expect if I have this condition?

Hypoxia usually requires medical treatment immediately. Your healthcare provider will talk to you about the underlying cause and how to manage it going forward.

In some circumstances, hypoxia resolves when the underlying condition is treated. In these cases, the need for supplemental oxygen goes away. In other circumstances, you may need chronic supplemental oxygen to ensure there is no ongoing hypoxia or tissue damage from low oxygen levels. Your healthcare provider will discuss your options with you.

(Video) Hypoxemia - The 5 Causes & Treatment... #1 High Altitude

Living With

How do I take care of myself?

If you have an underlying condition that led to — or could lead to — hypoxia, managing that condition is the best way to lower your risk of it happening again.

  • Don’t ignore new symptoms. Trust yourself if you feel something is off and contact your healthcare provider or go to the ER.
  • Take care of yourself. If you have asthma, know your triggers and make sure you have a rescue inhaler if prescribed. Perform breathing exercises using an incentive spirometer and follow any other recommendations for lung health provided by your healthcare provider.
  • Quit smoking and using tobacco products. If you smoke, quitting can help increase lung function and prevent further damage to your lungs.
  • Take any medication as prescribed by your healthcare provider.
  • Make a plan for high-altitude travel. Even those without underlying conditions can have trouble breathing at high altitudes. Understand how it might affect you and make a plan for how to adjust to the change. Think about what you will do if you need medical attention. Give yourself plenty of time to acclimate if necessary and make sure to bring any extra equipment or medication you might need.

When should I go to ER?

Hypoxia can be a life-threatening condition. Go to the emergency room if you have any symptoms of hypoxia or if others notice a sudden change in your behavior or awareness (confusion, restlessness, change in consciousness). Go to the ER if you have an ongoing medical condition and your typical symptoms worsen suddenly, or you experience new symptoms that you think might be hypoxia.

What questions should I ask my healthcare provider?

If you or a loved one is diagnosed with hypoxia, here are some questions you can ask your healthcare provider:

  • Is hypoxia related to an underlying medical condition?
  • How can I manage my condition to reduce my risk of hypoxia?
  • Did this cause any organ damage or other complications?
  • Are there any changes in lifestyle that could reduce my risk of hypoxia?
  • Do changes in travel plans or medication increase my risk of hypoxia?

A note from Cleveland Clinic

Hypoxia is a life-threatening condition that is treatable with prompt medical attention. If you have a heart or lung condition that puts you at risk for hypoxia, talk to your healthcare provider about the signs and symptoms to look for and what to do if you think your oxygen is too low. Trust that you know your body best and don’t hesitate to call your healthcare provider or go to the nearest ER if you experience any worrisome symptoms.


Is hypoxia a symptom or diagnosis? ›

Hypoxia is low levels of oxygen in your body tissues. It causes symptoms like confusion, restlessness, difficulty breathing, rapid heart rate, and bluish skin. Many chronic heart and lung conditions can put you at risk for hypoxia. Hypoxia can be life-threatening.

What is the best treatment for hypoxia? ›

Oxygen therapy can be utilized to treat hypoxemia. This may involve using an oxygen mask or a small tube clipped to your nose to receive supplemental oxygen. Hypoxemia can also be caused by an underlying condition like asthma or pneumonia.

How is hypoxia diagnosed? ›

In order to determine whether you have hypoxemia, your doctor will need to check the amount of oxygen in your blood. Most often, your doctor will use an oxygen monitor that is placed on your finger. However, sometimes your doctor will take a blood sample to measure oxygen levels in the blood.

What is the first symptom of hypoxia? ›

When your blood oxygen falls below a certain level, you might experience shortness of breath, headache, and confusion or restlessness. Common causes of hypoxemia include: Anemia.

Can a person recover from hypoxia? ›

A full recovery from severe anoxic or hypoxic brain injury is rare, but many patients with mild anoxic or hypoxic brain injuries are capable of making a full or partial recovery. Furthermore, symptoms and effects of the injury are dependent on the area(s) of the brain that was affected by the lack of oxygen.

Can you fix hypoxia? ›

The underlying condition causing hypoxia must be treated to manage and improve patient outcomes. For example, if hypoxia is caused by pneumonia, additional treatment for hypoxia may include antibiotics, increased fluid intake, oral suctioning, position changes, and deep breathing and coughing exercises.

What are the 4 types of hypoxia? ›

Hypoxia is actually divided into four types: hypoxic hypoxia, hypemic hypoxia, stagnant hypoxia, and histotoxic hypoxia.

What is the most common cause of hypoxemia? ›

1. V/Q Mismatch. This is by far the most common cause of hypoxemia. There is a big difference between the pressure that O2 is exerting within the alveoli (PAO2) and what it is able to exert in the arterial blood (PaO2).

Where does hypoxia usually occur? ›

Hypoxia occurs naturally but has increased since the 20th century due to human activity. Hypoxic conditions have been reported worldwide (Diaz and Rosenburg 2008). They occur most often in estuaries and coastal waters, but also in inland lakes, rivers, and streams (Jean-Philippe et al.

How long does hypoxia last for? ›

Most people will die within 10 minutes of total oxygen deprivation. Those in poor health often die much sooner. Some people may suffer other medical catastrophes, such as a heart attack, in response to oxygen deprivation.

Can hypoxia be treated with oxygen? ›

Hyperbaric oxygen therapy is a treatment for hypoxic- and inflammatory-driven conditions, in which patients are treated with 100% oxygen at pressures greater than atmospheric pressure.

What are the late signs and symptoms of hypoxia? ›

Common assessment findings during the late stage of hypoxia include symptoms such as cyanosis, cool, clammy skin, use of accessory muscles, retractions, hypotension, and arrhythmias. This is a bluish discoloration of the skin, which is caused by a decreased amount of oxygenated hemoglobin on red blood cells.

What are the risks of hypoxia? ›

Hypoxia can lead to many serious, sometimes life threatening complications.
Here are other complications of hypoxia:
  • Acute exacerbation of COPD. ...
  • Acute or chronic respiratory failure. ...
  • Pulmonary hypertension. ...
  • Cor pulmonale. ...
  • Bacterial infections.

Does hypoxia cause fatigue? ›

First hypoxia increased minute ventilation and consequently the work of breathing, therefore potentially leading to greater muscle fatigue. Second, hypoxia might enhanced blood flow competition between respiratory and locomotor muscles [14].

Can anxiety cause hypoxia? ›

Can Stress Cause Low Oxygen Levels? Stress can affect all systems of the body — even leading to lower oxygen levels in the blood and body. If you sometimes feel short of breath when you're stressed or anxious, you are not alone. This is a common symptom of anxiety.

Can hypoxia be permanent? ›

Cerebral hypoxia is a medical emergency. It can cause permanent brain injury. If the brain goes too long without oxygen, brain death and coma can occur.

How long does it take for hypoxia to damage the brain? ›

Brain cells are very sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death.

Can hypoxia damage lungs? ›

Hypoxia Exacerbates Inflammatory Acute Lung Injury via the Toll-Like Receptor 4 Signaling Pathway. Acute lung injury (ALI) is characterized by non-cardiogenic diffuse alveolar damage and often leads to a lethal consequence, particularly when hypoxia coexists.

Which part of the body is most sensitive to hypoxia? ›

Besides its immediate effects, hypoxia causes delayed functional and metabolic disturbances which may even progress to cell death. The brain regions most sensitive to this type of injury are parts of the hippocampus, the dorsolateral caudate nucleus and the reticular nucleus of thalamus.

What three other conditions can cause hypoxia? ›

Classic causes of hypoxia include hypoventilation, ventilation-perfusion mismatch, the low oxygen content in the air, right to left shunting, or impaired diffusion.

How does the body respond to hypoxia? ›

Body's Response to Hypoxia

In most tissues of the body, the response to hypoxia is vasodilation. By widening the blood vessels, the tissue allows greater perfusion. By contrast, in the lungs, the response to hypoxia is vasoconstriction.

What is a nursing diagnosis for hypoxia? ›

Commonly used NANDA-I nursing diagnoses for patients experiencing decreased oxygenation and dyspnea include Impaired Gas Exchange, Ineffective Breathing Pattern, Ineffective Airway Clearance, Decreased Cardiac Output, and Activity Intolerance.

How is hypoxia and hypoxemia diagnosed? ›

Pulse oximetry is a noninvasive test that measures blood oxygen saturation. It can directly detect hypoxemia. Blood oxygen levels can be a direct indicator of tissue oxygenation, so pulse oximetry can diagnose hypoxia as well.

What is hypoxia defined as? ›

Hypoxia is a state in which oxygen is not available in sufficient amounts at the tissue level to maintain adequate homeostasis; this can result from inadequate oxygen delivery to the tissues either due to low blood supply or low oxygen content in the blood (hypoxemia).

What does hypoxic mean in medical terms? ›

(hy-POK-sik) Having too little oxygen.

What are 5 nursing diagnosis? ›

NANDA-I recognizes four categories of nursing diagnoses: problem focused diagnosis, risk diagnosis, health promotion diagnosis, and syndrome. Problem focused diagnoses, also known as actual diagnoses, are patient issues or problems that are present and observable during the assessment phase.

What is the nursing intervention for hypoxia? ›

Deep breathing and coughing techniques help patients effectively clear their airway while maintaining their oxygen levels. Teach patients “controlled coughing” by having them take a deep breath in and cough deeply with the mouth slightly open. If they have difficulty coughing, teach the huffing technique.

What are the 4 types of nursing diagnosis *? ›

The four types of nursing diagnosis are Actual (Problem-Focused), Risk, Health Promotion, and Syndrome.

How do you know if a patient has hypoxia? ›

Hypoxemia is determined by measuring the oxygen level in a blood sample taken from an artery (arterial blood gas). It can also be estimated by measuring the oxygen saturation of your blood using a pulse oximeter — a small device that clips to your finger.

What medications can cause low oxygen levels? ›

Sometimes — and this may come as a surprise to you — the medications you take can cause it. Certain medications can lead to shortness of breath in a few different ways.
One of your medications might be causing your breathing symptoms.
  • Macrobid (nitrofurantoin) ...
  • Amiodarone. ...
  • NSAIDs. ...
  • Beta blockers. ...
  • Methotrexate. ...
  • Leflunomide.
Aug 8, 2022

Can you recover from hypoxia? ›

A full recovery from severe anoxic or hypoxic brain injury is rare, but many patients with mild anoxic or hypoxic brain injuries are capable of making a full or partial recovery. Furthermore, symptoms and effects of the injury are dependent on the area(s) of the brain that was affected by the lack of oxygen.

What is an example of hypoxia? ›

A high altitude, where the concentration of atmospheric oxygen is decreased. Deep sea diving if there is an inadequate supply of oxygen in the breathing gas or if a rusting cylinder has extracted oxygen, for example.


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4. Hypoxemia Explained Clearly - Causes, Physiology, Hypoxia, Treatment
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