Sign up for our newsletter
Get health tips, wellness advice, and more

Thanks for signing up!
You've been added to our list and will hear from us soon.

See all Healthline's newsletters »

Peripheral Cyanosis

What is peripheral cyanosis?

Cyanosis refers to a bluish cast to the skin and mucous membranes, such as the lips or inside the mouth. Peripheral cyanosis is when the bluish discoloration also affects the limbs. Typically, it’s caused by low oxygen levels in the red blood cells or problems getting oxygenated blood to the tissues. Rarely, it’s due to a high level of an abnormal protein within the red blood cells that blocks normal oxygen binding.

Blood that’s rich in oxygen is the bright red color typically associated with blood. But blood with a lower level of oxygen has a bluish or purple tint.

Sometimes cold temperatures can cause blood vessel narrowing and lead to blue-tinged skin temporarily. Warming or massaging the blue areas should return normal blood flow and color to the skin.

There may be an underlying disease or problem if the lips or the fingertips remain blue despite being warm. Whatever the underlying cause is, the blue coloring means that the disease or problem is interfering with the body’s ability to deliver oxygen-rich blood throughout the body. It’s important to restore oxygen to body tissues as soon as possible in order to prevent complications.

Causes of peripheral cyanosis


In peripheral cyanosis, the bluish color can be due to slow blood flow to an area with constriction (narrowing) of the blood vessels. This can occur with:

  • exposure to cold
  • shock
  • congestive heart failure
  • peripheral vascular disease

Other times, peripheral cyanosis is due to low oxygen states. Some of the causes of low oxygen are:

  • pneumonia
  • carbon monoxide poisoning
  • cardiac tamponade, or fluid buildup in the heart
  • emphysema
  • pulmonary embolism
  • shock
  • congestive heart failure
  • chronic obstructive pulmonary disease (COPD)
  • pulmonary edema, fluid in the lungs
  • cor pulmonale, an enlargement of the right ventricle in the heart
  • septicemia, a life-threatening blood infection
  • respiratory syncytial virus infection or other respiratory infections

Diagnosing peripheral cyanosis


Bluish skin is usually a sign of something serious. If normal color doesn’t return when your skin is warmed, you should seek urgent medical attention in order to determine the cause.

Your doctor will need to perform a physical examination. They will also listen to your heart and lungs. You will likely have to provide a blood sample and undergo other tests.

Your doctor may use a noninvasive pulse oximeter to measure the oxygenation of your blood. They may also order an arterial blood gas test. This test measures the acidity and the levels of carbon dioxide and oxygen in your blood. You may also order a chest X-ray or CT scan to evaluate your heart and lungs.

Recognizing a medical emergency

In many cases, blue lips or skin can be a sign of an immediate life-threatening emergency. If your blue discoloration is accompanied by any of the following, call 911:

  • air hunger or gasping for breath
  • fever
  • headache
  • shortness of breath or breathing difficulties
  • chest pain
  • sweating profusely
  • pain or numbness in the arms, legs, hands, fingers, or toes
  • pallor or blanching of the arms, legs, hands, fingers, or toes
  • dizziness or fainting

Treating peripheral cyanosis


It’s important to seek medical attention for new peripheral cyanosis. Treatment involves identifying and correcting the underlying cause in order to restore the oxygenated blood flow to the affected parts of the body. Receiving the proper treatment in a timely manner will help improve the outcome and limit complications.

Read This Next