What is the Difference Between Cyanosis and Pallor

The key difference between cyanosis and pallor is that cyanosis is the bluish color of skin, nails, and lips mainly due to the low level of oxygen in the blood, while pallor is the abnormal pale or lighter appearance of skin and mucous membranes due to anemia.

Cyanosis and pallor are two conditions related to the skin and mucous membranes. In cyanosis, skin, nails, and lips become bluish-purple-colored due to blood having low levels of oxygen. Therefore, cyanosis can be defined as the bluish-purple hue mainly in the skin. Pallor, on the other hand, can be mainly defined as an unusually pale color of the skin.

CONTENTS

1. Overview and Key Difference
2. What is Cyanosis 
3. What is Pallor
4. Similarities – Cyanosis and Pallor
5. Cyanosis vs Pallor in Tabular Form
6. Summary – Cyanosis vs Pallor

What is Cyanosis?

“Cyan” stands for blue. Cyanosis is a condition characterized by the bluish discoloration of the skin and the mucous membranes. This condition is due to the low level of oxygen in the blood. In other words, cyanosis occurs when there is an increase in the deoxygenated hemoglobin level above 5 g/dL. There are three types of cyanosis as peripheral, central, and differential cyanosis. Peripheral cyanosis mainly occurs due to diminished peripheral blood flow. On the other hand, central cyanosis mainly occurs due to decreased arterial oxygen saturation.

Peripheral cyanosis affects the extremities of the body. The symptoms of this condition may include the skin on fingertips, toes, palms, or feet appearing bluish and greenish, a cold sensation in the affected body, and the color returning to normal after the area warms up. The common causes of peripheral cyanosis may include Raynaud’s disease, low blood pressure, hypothermia, problems with arteries, heart failure, deep vein thrombosis, and hypovolemic shock.

Central cyanosis affects the core organs of the body. It causes a blue to green tint on lips, tongue, or on both. In this type of cyanosis, the symptoms do not get better when the body part is heated up. This is a kind of cyanosis normally seen in people suffering from heart or lung diseases and certain abnormal medical conditions, including methemoglobinemia and sulfhemoglobinemia. The other causes include birth injury or asphyxia, transient tachypnoea, pneumothorax, lung edema, lung thromboembolism, chronic obstructive lung disease, etc. The symptoms of central cyanosis include bluish discoloration on the tongue and lips, chest pain, rapid breathing, difficulty breathing, squatting, fever, irritability, fussiness, poor feeding, poor sleeping in infants and young children, lethargy, and frequent headaches. Differential cyanosis is the bluish discoloration in the different parts of the body. In differential cyanosis, the lower extremity mainly appears as bluish, while the upper extremity and the head are pink.

Cyanosis is not a disease. It is a very important clinical sign of an underlined medical condition. Hence, it should be managed well. People should be aware of the risk factors and measures in order to avoid life-threatening complications.

What is Pallor?

“Palleo” in Latin stands for pale or fade. Pallor is the condition of the skin and mucous membranes where they appear pale or lighter than the usual color. Pallor can be seen in the skin all over the body or in a particular area. The main reason for pallor is anemia. However, there are several other reasons as well, including chemical poisoning, folic acid deficiency, arterial occlusion, cancer, lack of sleep, kidney problems, excessive bleeding, lack of sun exposure, infections, fear or panic, and malnutrition.

Pallor is considered to be a serious condition if the paleness appears on certain areas, including lips, the lining of the eyes, palms of the hands, inside the mouth, and the surface of the tongue. Pallor can be diagnosed by sight or by checking inner eyelids and mucous membranes for a loss of color. There are several other tests to diagnose pallor. Complete blood count (CBC), reticulocyte count, fecal blood test, thyroid function tests, kidney function tests, tests for nutrient deficiencies, noninvasive imaging tests, extremity arteriography, and serum pregnancy test are some of the diagnostic methods of pallor.

What are the Similarities Between Cyanosis and Pallor?

• Both cyanosis and pallor ate two conditions of the skin.
• They can be seen on lips, tongue, palms, inside the mouth, etc., as well.
• They are due to abnormal conditions of the blood.
• In both conditions, the color of the skin turns into abnormal color.
• They can be a sign of an underlined medical condition.

What is the Difference Between Cyanosis and Pallor?

Cyanosis is the bluish discoloration of the skin and mucous membranes, while pallor is the pale or lighter appearance of the skin and mucous membranes. Thus, this is the key difference between cyanosis and pallor. Cyanosis occurs mainly due to low oxygenated hemoglobin in the blood. In contrast, pallor is due to anemia or lack of enough red blood cells in the blood.

Below is a summary of the difference between cyanosis and pallor in tabular form for side-by-side comparison.

Summary – Cyanosis vs Pallor

Skin is the largest organ of our body, and skin color is a good indication of the overall health of a person. Cyanosis and pallor are two clinical signs that may reflect underlying medical conditions. In cyanosis, skin and mucous membranes turn into a bluish-purple color. In pallor, skin and mucous membranes turn into pale or whitish color than the usual color. Cyanosis may be a good indication of hypoxemia, while pallor can be a good indication of anemia. So, this is the summary of the difference between cyanosis and pallor.

Reference:

1. “What Causes Pallor? the Conditions That Cause Pallor, Diagnosis, and Treatment.” WebMD.
2. “Central and Peripheral Cyanosis.” Statpearls – NCBI Bookshelf.

Image Courtesy:

1. “Peripheral Cyanosis due to Ischemia” By James Heilman, MD – File:Ischemia.JPG (CC BY-SA 4.0) via Commons Wikimedia
2. “Scarlet fever 1” By Estreya at English Wikipedia – Transferred from en.Wikipedia to Commons (Public Domain) via Commons Wikimedia