Peripheral cyanosis is when the hands, fingertips, or feet turn blue because they are not getting enough oxygen-rich blood.

All organs and tissues need oxygen to function. A person’s body absorbs oxygen from the air that they breathe. Blood contains a protein called hemoglobin that carries oxygen to the body’s cells. If the blood cannot deliver enough oxygen to an area of the body, cyanosis may occur.

The condition gets its name from the word “cyan,” a blue-green color. The primary symptom is blue discoloration of the skin.

“Peripheral” cyanosis affects the extremities. Cold temperatures, circulation problems, and tight jewelry are common causes.

Often, cyanosis is not serious. However, some underlying causes are. A person should seek medical attention if they develop the symptoms.

This article takes a close look at peripheral cyanosis, including its causes, symptoms, and treatment. It also looks at another type called central cyanosis, which affects core organs in the body, as well as the lips, tongue, or both.

A person with peripheral cyanosis may notice that:

  • The skin on fingertips, toes, palms, or feet appears bluish or greenish.
  • The affected body part feels cold to the touch.
  • The color returns to normal after the area warms up.

Certain medical conditions can prevent oxygen-rich blood from reaching parts of the body. Some people are born with hemoglobin that has a limited ability to bind to oxygen and carry it to the cells.

People tend to experience cyanosis in the extremities, such as the fingertips and feet, because these areas are farthest from the heart, so the blood has longer to travel.

Common causes of peripheral cyanosis include:

  • Raynaud’s disease. This causes the fingertips and toes become numb, as well as bluish or whitish, in cold temperatures. The blood vessels narrow, preventing blood from reaching the extremities.
  • Low blood pressure. Low blood pressure can keep enough blood and oxygen from reaching the hands and feet.
  • Hypothermia. This involves the body’s temperature dropping dangerously low. It is a medical emergency.
  • Problems with an artery. If a health condition affects an artery that delivers blood and oxygen to the hands and feet, peripheral cyanosis may result.
  • Heart failure. This can prevent the heart from pumping blood around the body effectively.
  • Deep vein thrombosis. If a clot forms in a vein in the leg, for example, peripheral cyanosis may develop in that limb.
  • Hypovolemic shock. When this happens, the body body diverts blood from the skin toward the internal organs.

What is central vs. peripheral cyanosis?

The key difference involves the area of the body affected.

Peripheral cyanosis develops in the hands or legs, especially in the more remote extremities, such as the fingertips, fingernails, and feet. It may affect areas on just one or both sides of the body.

Central cyanosis affects the core organs of the body. Central areas develop a blue-green tint, as do the lips, tongue, or both. The symptoms of central cyanosis do not get better when the body part is heated up.

Central and peripheral cyanosis have some similar causes, including problems with the heart, blood, lungs, or nervous system.

Doctors evaluate peripheral cyanosis through a combination of tests, such as blood work, and imaging scans, such as X-rays. This helps doctors assess the level of oxygen in the blood and determine the cause of the cyanosis.

In someone with cyanosis, a test typically shows unsaturated hemoglobin levels of 5 grams per deciliter of blood. Unsaturated hemoglobin does not carry oxygen. This result indicates at most 85% oxygen in the blood, which is too low.

These tests can also indicate the presence of other conditions that affect the heart or lungs, or otherwise alter oxygen levels.

Treatment for peripheral cyanosis depends on the underlying cause of the problem.

Doctors may prescribe medications to treat heart and lung conditions. These help improve blood flow and oxygen supply to the organs and tissues. Some people may need oxygen therapy to restore healthy levels.

Doctors may also recommend stopping any treatments that restrict blood flow, including beta blockers, birth control pills, and certain allergy medications. And they may recommend lifestyle changes such as quitting smoking, if this applies, or cutting out caffeine.

Peripheral cyanosis is a symptom of a health issue rather than a medical condition in itself.

Is cyanosis an emergency?

Some causes can be life threatening. If a person has cyanosis and any of these symptoms, they need immediate medical care:

  • difficulty breathing, such as gasping for breath
  • chest pain
  • profuse sweating
  • sudden pain or numbness in the arms, legs, hands, or feet
  • inability to concentrate or disorientation
  • a fever or any other flu-like symptoms

Peripheral cyanosis can occur in anyone, including newborns. In babies, the issue may be related to the heart, nerves, lungs, or cell functioning.

It can be difficult to detect peripheral cyanosis in babies, particularly in newborns, because other factors, such as jaundice, may mask the blue-green tinge.

Peripheral cyanosis is usually not a medical emergency. Central cyanosis is more likely to be a sign of something that requires immediate medical attention.

Below, we answer some common questions about cyanosis.

How do you cure cyanosis?

Since cyanosis is a symptom of another condition, the best way to cure it is to diagnose and treat the underlying cause.

What are the other types of cyanosis?

We describe central and peripheral cyanosis above. Another type is differential cyanosis. This also presents as blue discoloration in the extremities. It is a serious condition that usually indicates a life threatening problem with the heart or lungs.

The outlook depends on the cause of the cyanosis and how severe it is.

If a person notices a bluish or greenish tinge to their extremities, they should try warming the areas up, such as by massaging them to increase blood flow. Consult a doctor if the color change does not go away.

A timely diagnosis and treatment at an early stage can help prevent complications.