What causes blue lips?

Blue lips are usually caused by a lack of oxygen in the blood, although they may also be caused by extreme cold. Decreased oxygen levels in the blood can be due to a variety of underlying conditions.

Acute causes of blue lips

Blue lips may be caused by conditions, events or environments that are short term in nature including:

  • Exposure to extreme cold
  • High altitude
  • Toxic exposure
  • Poisoning

Respiratory system conditions that may cause decreased blood oxygen leading to blue lips

Blue lips may be caused by chronic underlying conditions that lead to a decrease in blood oxygen levels including:

  • Asthma
  • Chronic obstructive pulmonary disease (COPD, which includes emphysema and chronic bronchitis)
  • Lung cancers
  • Pneumonia
  • Pulmonary hypertension (high blood pressure in the arteries of the lungs)

Other conditions that may cause decreased blood oxygen leading to blue lips

Conditions involving other body systems can also decrease oxygen levels and lead to blue lips including:

  • Anemia (low red blood cell count)
  • Congenital heart defects
  • Congestive heart failure (deterioration of the heart’s ability to pump blood)
  • Croup (viral illness)
  • Epiglottitis (life-threatening inflammation and swelling of the epiglottis, a tissue flap between the tongue and windpipe)
  • Heart attack (myocardial infarction)
  • Methemoglobinemia (abnormal hemoglobin that can be caused by certain medications or toxins)
  • Raynaud’s phenomenon (spasms of small blood vessels of the fingers and toes, reducing blood circulation; Raynaud’s phenomenon is secondary to many autoimmune disorders such as lupus)
  • Smoking

Serious or life-threatening causes of blue lips

Blue lips are usually a sign of a low blood-oxygen level and is a serious symptom that should often be evaluated in an emergency setting. If you have blue lips with other serious symptoms, seek immediate medical attention (call 911). These other symptoms include:

  • Choking
  • Poisoning
  • Prolonged seizure
  • Pulmonary embolism (blockage of an artery in the lung due to a blood clot that breaks loose from another site)
  • Respiratory failure and respiratory arrest
  • Suffocation

Questions for diagnosing the cause of blue lips

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your blue lips including:

  • When did you first notice your blue lips?
  • Was the onset of your symptom sudden?
  • Are you having difficulty breathing?
  • Have you been at high altitude?
  • Have you been exposed to very cold temperatures?
  • Are you having any other symptoms?
  • Are you taking any medications?
  • Do you have any other medical conditions?

What are the potential complications of blue lips?

Blue lips can be an indication of a serious underlying condition or disease. Prompt evaluation from a medical professional can help to identify the source of your blue lips. Once the underlying condition or disease is identified, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Heart failure
  • Permanent disability
  • Respiratory failure and respiratory arrest
  • Spread of cancer
  • Spread of infection
  • Stroke


  1. Skin discoloration - bluish. MedlinePlus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003215.htm.
  2. Cyanotic heart disease. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/001104.htm.
  3. Kahan S, Miller R, Smith EG (Eds.). In A Page Signs & Symptoms, 2d ed. Philadelphia: Lippincott, Williams & Williams, 2009.

What are blue lips?

Blue lips occur when the skin on the lips takes on a bluish tint or color. This generally is due to either a lack of oxygen in the blood or to extremely cold temperatures. When the skin becomes a bluish color, the symptom is called cyanosis.

Most commonly, blue lips are caused by a lack of oxygen in the blood. This may happen when you are at high altitude or if you are choking, o... Read more about blue lipsintroduction


What other symptoms might occur with blue lips?

Blue lips are generally due to a lack of oxygen in the blood. Often, this can be caused by an underlying condition that may cause other symptoms.

Symptoms that may occur along with blue lips

Blue lips may accompany other symptoms caused by underlying conditions or due to events that lead to a lack of oxygen in the blood including:

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Aug 23, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

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