Hypoventilation

Symptoms, Causes, and Treatment

Medically reviewed by Susan Russell, MD

Hypoventilation, or shallow, short breathing, causes carbon dioxide to build up in the blood and decreases oxygen levels. Causes include having obesity, genetic mutations, and certain underlying conditions. For some people, there is no known cause.

A healthcare provider may perform one or more tests to determine the underlying cause of hypoventilation and determine the best treatment approach.

This article discusses the symptoms and potential causes of hypoventilation. It will also cover risk factors and when to seek tests or treatment for symptoms.  

Critical Symptoms

If you are experiencing symptoms such as blue skin or lips, chest pain, or shortness of breath, call 911 immediately.

Symptoms of Hypoventilation

Short, shallow breaths characterize hypoventilation. It can lead to carbon dioxide buildup and decreased oxygen, causing additional symptoms, including the following:

• Breathlessness

• Daytime drowsiness

• Dizziness

• Fatigue

• Morning headaches

• Feeling unrested in the mornings

• Waking up a lot at night

• Snoring

• Choking, gasping, or breathing problems during sleep

Causes of Hypoventilation

There are various potential causes of hypoventilation. The most common causes are:

• Sleep apnea

• Pickwickian syndrome

• Primary alveolar hypoventilation

• Congenital central hypoventilation syndrome
  

Pickwickian syndrome, also called obesity hypoventilation syndrome, is a breathing condition in some people experiencing obesity. Excess weight is a risk factor for this condition since extra weight around the neck, face, and stomach can make it hard to take deep breaths. Being overweight also produces excess hormones that can impact breathing patterns.

Primary alveolar hypoventilation is a rare disorder with shorter breaths per minute. The primary cause is unknown. The lungs and airways usually appear normal.

Congenital central hypoventilation impacts your breathing due to a genetic mutation in the PHOX2B gene, which instructs the body to make a protein that helps support nerve cell formation in the autonomic nervous system. This part of your nervous system controls involuntary bodily functions, like breathing, heart rate, and blood pressure. The PHOX2B mutation makes these functions unregulated.

Sleep apnea is a condition in which your breathing pauses during sleep. Symptoms include snoring or gasping in your sleep, poor quality sleep, or daytime sleepiness.

What Is the Treatment for Hypoventilation?

Treatment options depend on what is causing hypoventilation. Options include medications,  mechanical devices, or lifestyle changes to lose weight, such as:

• Respiratory stimulants trigger the respiratory center in the brain stem and medulla to improve breathing. Medications such as the injectable doxapram or oral bronchodilators such as caffeine, theophylline, and aminophylline, treat hypoventilation.

• CPAP (continuous positive airway pressure) is a device that uses mild air pressure to keep your airways open during sleep. A CPAP machine includes a mask that fits over your nose and mouth using straps and a tube that connects the mask to the machine’s motor.

• Lifestyle changes to help prevent hypoventilation include healthy eating, physical activity, and stress reduction.
  

Tests to Diagnose Hypoventilation

In addition to a physical exam, a healthcare provider may perform one of the following tests to diagnose hypoventilation:

• Arterial blood gas test: This measures your blood's oxygen, carbon dioxide, and acidity levels. Results will show how well your lungs take in oxygen into your blood when you inhale and how well they remove carbon dioxide from your blood when you exhale.

• Chest X-ray or CT (computed tomography) scan: A chest X-ray can help a healthcare provider diagnose lung problems such as pneumonia, pulmonary edema, or pleuritis (inflammation of the lung lining). A healthcare provider may order a CT scan if they see something unusual in a chest X-ray since CT scans provide more detailed imaging.

• Hematocrit and hemoglobin blood tests: A hematocrit test measures how many red blood cells are in your blood. This is important because red blood cells carry oxygen from your lungs to the rest of your body. Hemoglobin is a protein that helps red blood cells carry oxygen from your lungs. Low or high levels of hematocrit or hemoglobin can cause health problems.

• Lung function tests: These tests determine how well the lungs are working. Spirometry measures how much air the lungs can hold and how forcefully you can empty air from your lungs. Other tests include lung volume, diffusing capacity (how easily oxygen enters the blood), and exercise testing.

• Overnight oximetry: Pulse oximetry is a non-invasive test measuring blood oxygen saturation. Testing this overnight can detect sleep-disordered breathing that impacts blood oxygen levels.

• Sleep study: This overnight test evaluates problems in your body or brain during sleep by monitoring eye movement, oxygen levels, heart rate, breathing rate, snoring, and body movements.
  

When to See a Healthcare Provider

Some signs and symptoms indicate you need to see a healthcare provider, while others may require emergency medical attention.

Call your healthcare provider if you notice any of the following symptoms:

• Extreme fatigue

• Daytime drowsiness

• Leg or ankle swelling

• Feeling like you never get a good night’s rest

Contact 911 right away if you experience the following:

• Skin turning blue (this indicates low blood oxygen)

• Shortness of breath

• Chest pains

• Fatigue, drowsiness, or sudden swelling
  

Summary

Hypoventilation develops when oxygen levels are too low, and carbon dioxide levels are too high. The most common causes of hypoventilation are being a person with obesity, a genetic mutation, and sleep apnea. A healthcare provider can determine how to diagnose hypoventilation using various tests.

There are many treatment options for hypoventilation, though treatment response varies. If you are undergoing treatment for hypoventilation, follow your healthcare provider's recommendations closely and contact them before making changes to your treatment plan.