Word of the Week: Cyanosis

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Each week, Verywell explains a term from health, medicine, science, or technology.

Word of the Week: Cyanosis

How to say itCyanosis (sigh-a-no-sis)

What it means: A bluish discoloration to the skin caused by a lack of oxygen in the blood.

Where it comes from: From Latin, kyanōsis, "dark blue color."

A patient's open hand showing a blue tint to the tips of their fingers.


Where you might see or hear it: One of the most important roles that your blood plays in your body is transporting oxygen. Not having enough oxygen in your blood can cause problems and can be a sign of several health conditions.

For example, your doctor might note a bluish tint to some parts of your body (your lips, hands and feet, your nail beds, or even your gums) if you have an infection like pneumonia that is making you have trouble breathing.

When you might want to use it: Having a bluish tint to your skin or mucus membranes is usually a sign that your body is not getting enough oxygen. When it comes on suddenly, involves the lips or mouth, and especially when it happens in babies and kids, cyanosis can be a medical emergency.

In that situation, using the correct medical term will probably be the last thing on your mind. You can simply tell an emergency responder or doctor that your child's lips are turning blue rather than worry about remembering the word "cyanosis."

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