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Cyanosis (Blue colouration of lips, feet, body):
Diagnosis and treatment



1. What is Cyanosis?

Cyanosis is an unusual bluish cast or discoloration of the skin and mucous membranes, which is commonly noticed around the lips, mouth, palms of the hands, fingernails and soles of the feet.

The nomenclature Cyanosis, very literally means the blue disease or the blue condition. It is derived from the colour cyan, which comes from cyanós (κυανός), the Greek word for blue.

This condition commonly called “blue hands or feet,” signifies hypoxemia, or an abnormally low level of oxygen in the blood. It is also called deoxygenated haemoglobin.

High levels of deoxygenated haemoglobin within the superficial vessels of the skin cause this bluish appearance. Cyanosis is most pronounced where the overlying epidermis is thin, and the area has a rich network of blood vessels.

When the amount of reduced haemoglobin exceeds 5 gm% in the capillaries, the blood appears dark, giving the tissues a bluish hue.



2.Types of Cyanosis

Cyanosis can be divided into Central Cyanosis, Peripheral Cyanosis, Differential Cyanosis, or Cyanosis, amongst new-borns and babies.

Central Cyanosis

Central Cyanosis is a blue discoloration seen on the tongue and lips, and is due to lower levels of oxygen in the Central arterial blood; caused by cardiac or respiratory disorders.

Those suffering from Central Cyanosis will usually have Peripheral Cyanosis, which is a bluish or purple discoloration of the fingers and toes.

A type of Central Cyanosis could also occur when an abnormal pigment in the blood due to a drug intake or any other reason, imparts the abnormal bluish colour to the skin.

Peripheral Cyanosis

Peripheral Cyanosis is a blue or purple skin discoloration of the extremities, viz. fingers and toes, and is most intense in nail beds, especially if the external temperature gets really cold.

Differential Cyanosis

Differential or Mixed Cyanosis is diagnosed when the bluish discoloration is present in certain parts of the body and absent in others. It could be present only in the lower limbs, or only in the upper limbs, or only in the left upper and both lower limbs.

Cyanosis in new-borns and babies

Cyanosis in new-borns or babies, Cyanosis is commonly observed in the area around a baby’s mouth. Sometimes even the palms, soles of the feet, head, or torso turn blue. This a sign that the Cyanosis baby is not getting enough oxygen. Transient Cyanosis clears a few minutes after birth.

Central Cyanosis in new-borns, infants and young children, requires urgent admission and medical assessment.



3.Causes of Cyanosis

The underlying causes of Cyanosis, or blue hands or feet or blue fingernails, is the tissues of the body do not receive blood with the requisite levels of oxygen, this can happen due to a variety of reasons.

The blood is responsible for carrying oxygen through your body. Blood makes the journey from your lungs, where deoxygenated blood is replenished with oxygen from the air you breathe. This oxygenated blood travels to your heart, where it is pumped through your arteries to the rest of your body. Upon delivering the blood to your body’s tissues, the deoxygenated blood returns to your heart and lungs, through your veins.

A variety of conditions could prevent blood from reaching your tissues, or from returning to your heart through your veins. This results in your tissues not receiving the oxygenated blood needed, and the subsequent bluish discolouration.

Let’s now look at the underlying Cyanosis causes for each type.

Central Cyanosis Causes

Central Cyanosis is very often caused by a circulatory or ventilatory issue. This in turn could lead to poor blood oxygenation in the lungs. Central Cyanosis develops when the arterial oxygen saturation goes below 85% or 75%.

Acute Cyanosis is a condition that could result from asphyxiation or choking. It is amongst the sure signs of respiration being blocked.

Central Cyanosis may be caused by the following issues:

1. Central nervous system related conditions (impairing normal ventilation):

  • Intracranial haemorrhage
  • Drug overdose (e.g. heroin)
  • Tonic–colonic seizure (e.g. grand mal seizure)

2. Respiratory system related conditions:

  • Pneumonia
  • Bronchiolitis
  • Bronchospasm (e.g. asthma)
  • Pulmonary hypertension
  • Pulmonary embolism
  • Hypoventilation
  • Chronic obstructive pulmonary disease, or COPD (emphysema)

3. Cardiovascular disease related conditions:

4. Blood-related conditions:

  • Methemoglobinemia
  • Polycythaemia
  • Congenital Cyanosis

5. Other conditions:

  • High altitude may trigger off Cyanosis, which may be observed when ascending to altitudes over 2400mts
  • Hypothermia
  • Obstructive sleep apnea

Peripheral Cyanosis Causes

Peripheral Cyanosis is a bluish tint observed in the fingers or toes, caused by suboptimal or restricted blood circulation. Blood reaching the fingers and toes is not oxygen-rich enough; when observed through the skin, it gives off the appearance of a blue colour.

All the conditions that cause Central Cyanosis, can also cause Peripheral symptoms to appear. Peripheral Cyanosis can sometimes be noticed even in the absence of heart or lung failures. Small blood vessels could be constricted and may be treated by boosting normal oxygenation levels of the blood.

Peripheral Cyanosis could sometimes occur due to the following:

  • All the common causes of Central Cyanosis
  • Reduced cardiac output (e.g. heart failure or hypovolaemia)
  • Cold exposure
  • Chronic obstructive pulmonary disease (COPD)
  • Arterial obstruction (e.g. Peripheral vascular disease, Raynaud phenomenon)
  • Venous obstruction (e.g. deep vein thrombosis)

Differential or Mixed Cyanosis Causes

This condition is normally observed especially in patients with a patent ductus arteriosus. Patients with a large ductus develop progressive pulmonary vascular disease, and pressure overload of the right ventricle occurs. As soon as pulmonary pressure exceeds aortic pressure, shunt reversal (right-to-left shunt) occurs. Upper extremity of the body remains pink in colour because the brachiocephalic trunk, left common carotid trunk, and the left subclavian trunk is given off proximal to the PDA.



4.Symptoms of Cyanosis

Cyanosis treatment

1. Age-related and the nature of Cyanosis onset:

  • Cyanosis caused by congenital heart disease, which in turn causes anatomical right-to-left shunts, that may have been prevalent from birth or the early years of life.
  • Acute onset ofCyanosis, which could be caused by conditions like pulmonary emboli, cardiac failure, pneumonia or asthma.
  • People suffering from COPD (Chronic Obstructive Pulmonary Disease) may develop Cyanosis over time and an associated condition called polycythaemia may exacerbate the intensity of Cyanosis.

2. Previous history: Cyanosis may also be caused by any lung disease of sufficient intensity.

3. Drug history: there are a set of drugs that may result in methemoglobinemia (e.g. nitrates, dapsone) or sulfhemoglobinemia (e.g. metoclopramide).

4. Associated symptoms:

  • Pain in the chest: Cyanosis that is associated with pleuritic chest pains could be caused by pulmonary embolism or pneumonia. Pulmonary oedema could cause dull, painful chest tightness.
  • Dyspnoea: this is a condition that may suddenly occur in conjunction with pulmonary emboli, pulmonary oedema or asthma.
  • Gasping for or shortness of breathing difficulties
  • Fever
  • Headache
  • Profuse sweating profusely
  • Pain or numbness in the arms, legs, hands, fingers, or toes
  • Paling or whitening of the arms, legs, hands, fingers, or toes
  • Dizziness or fainting.
  • Temperature: conditions like pneumonia and pulmonary emboli that could be with pyrexia.

The patient will also exhibit symptoms like:

  • Central Cyanosis - this condition produces a bluish discolouration, specially noticed on the mucous membranes of the lips, tongue, fingers and toes.
  • Peripheral Cyanosis - this condition affects the fingers, toes and skin surrounding the lips, is not noticed around mucous membranes.
  • A combination of clubbing and Cyanosis is frequent observed in congenital heart disease; it may be prevalent in pulmonary diseases, like lung abscess, bronchiectasis, cystic fibrosis; as also in pulmonary arteriovenous shunts.
  • Pressure in the jugular venous system increases with congestive cardiac failure.

After a respiratory examination:

  • Poor chest expansion is a condition that is noticed in patients with chronic bronchitis, and asthma. Reduced chest expansion may be noticed with conditions like lobar pneumonia.
  • Dullness to percussion is sometimes noticed in an area of consolidation.
  • Crepitation that is localised may sometimes be heard in conditions like lobar pneumonia. Crepitation is often more likely in conditions like bronchopneumonia and pulmonary oedema. Entry of air may be low with conditions like COPD or asthma. Bronchial breathing may be affected and wheezing sounds may sometimes be heard, in conditions like asthma.

Abnormal heart sounds that are sometimes heard, may suggest origins in the cardiac area.

Features that are localised may indicate aetiology of Peripheral Cyanosis. These could cover oedema in venous insufficiency or absence of Peripheral pulses and an ischaemic condition in arterial occlusion



5.Diagnosis of Cyanosis

Cyanosis Diagnosis

Bluish skin is usually a sign of something serious. If normal colour does not return when your skin is rubbed or warmed, it is important to get medical attention right away to determine the cause.

The physical examination performed by your doctor will include listening to your heart and lungs. You may also have to undergo a series of other clinical tests.

Apart from the clinical assessment of hypoxemia, the diagnosis of Cyanosis may also include the following investigations:

  • Arterial Blood Gas test: measures the acidity and levels of carbon dioxide and oxygen in your blood.
  • Complete Blood Count: Haemoglobin levels are increased with the prevalence of chronic Cyanosis. The white cell count increases in conditions like pneumonia and pulmonary embolism.
  • ECG: Taken to completely rule out the prevalence of cardiac abnormalities.
  • Chest X-ray: the is taken to rule out conditions like pneumonia, pulmonary infarction and cardiac failure.
  • Ventilation-perfusion scan or Pulmonary Angiography is taken to rule out pulmonary causes
  • Echocardiography will serve to look for the presence of any cardiac defects.
  • Haemoglobin spectroscopy will look for methemoglobinemia, or sulfhemoglobinemia.
  • Digital Subtraction Angiography: is done to completely rule out conditions like acute arterial occlusion.
  • A duplex Doppler or Venography can detect the prevalence of acute venous occlusion.



6.Cyanosis Treatment

You must seek medical attention if you have blue hands or feet, and warming them up doesn’t restore normal colour. The treatment involves identifying and correcting the underlying cause in order to restore the oxygenated blood flow to the affected parts of the body.

Receiving proper treatment in a timely manner will improve the outcome and limit any complications. It is important that any medication in Cyanosis Treatment should always be under the prescription and guidance of a registered medical practitioner.

There are some medications that can help blood vessels relax. These include:

  • antidepressants
  • antihypertensive drugs
  • erectile dysfunction drugs

You may also need to avoid certain medications that constrict blood vessels as a side effect. These include types of:

  • beta-blockers
  • migraine medications
  • birth control pills
  • pseudoephedrine-based cold and allergy medicines

Serious medical situations, such as heart or pulmonary related conditions, should be treated in a hospital as an emergency.

Conditions, such as Raynaud’s phenomenon, may require longer term lifestyle changes. These include avoiding caffeine and nicotine, both of which can cause your blood vessels to constrict.



7. Cyanosis FAQs: All your concerns addressed

Q.  What is Cyanosis?

  1. Cyanosis is generally a medical condition in which there's a blue tint to the skin, indicating the body is not receiving enough oxygen-rich blood.

Q.  What is cyanosis a symptom of?

  1. Cyanosis occurs when oxygen-depleted (deoxygenated) blood, which is bluish rather than red, circulates through the skin. Cyanosis can be caused by many types of severe lung or heart disease that cause levels of oxygen in the blood to be low.

Q.  What are the principal reasons for cyanosis?

  1. The three primary reasons of cyanosis include - Decreased pumping of blood by the heart or
    reduced cardiac output often seen in heart failure or circulatory shock; Diseases of
    circulation like thrombosis or embolism, and constriction of blood vessels of the limbs,
    fingers, and toes (due to exposure to cold, spasm of the smaller skin capillaries or arteries
    called acrocyanosis).
    The other leading causes of Cyanosis in both adults and newborns include:

    ● Birth injury (Asphyxia)
    ● Pulmonary or Lung Edema
    ● Diaphragmatic Hernia
    ● Severe Pneumonia
    ● Chronic Obstructive Lung Disease
    ● Acute Adult Respiratory Distress Syndrome

Q.  Is cyanosis a sign of a heart attack?

  1. In heart failure, lung embolism, pneumonia, or acute severe attack of asthma, the cyanosis may have a sudden or abrupt onset as the patient ‘begins to turn blue’ due to lack of oxygen. On the other hand, patients with chronic obstructive lung disease or COPD often develop cyanosis gradually over many years.

Q.  Should I treat blue lips in my child?

  1. It's common for new-borns to have some areas of blue skin once in a while. But if your baby's lips, mouth, head, or trunk are blue, seek emergency medical help.

Q.  What's the cause of my baby's skin turning blue?

  1. There are two reasons why the blood under your baby's skin may look blue:
  1. The lungs are not getting enough oxygen. Since it is the oxygen that makes the blood turn red in colour, blood cells without oxygen remain blue.
  2. The underlying blood is displays a slow movement, so the normal veins underneath that carrying blue, oxygen-poor blood back to the heart are more noticeable.

Q.  Can anemia cause cyanosis?

  1. Cyanosis is caused by an increase in the deoxygenated hemoglobin level to above 5 g/dL. Patients who have anemia do not develop cyanosis until the oxygen saturation (also called SaO2) falls below normal hemoglobin levels.

Q.  How long does Cyanosis last?

  1. It is a common finding and may persist for 24 to 48 hours. Central cyanosis caused by reduced arterial oxygen saturation lasts for nearly 5 to 10 minutes in a newborn infant as the oxygen saturation rises to 85 to 95 percent by 10 minutes of age.

Q.  How to differentiate between mild cyanosis and severe cyanosis?

  1. Babies who suffer from cyanotic heart disease are often referred to as “Blue Babies”. To determine if the cyanosis is mild or severe can be done by analyzing the following:


    • The nature of the defect
    • The age of the child
    • The level of activity


    In general, cyanosis is known to worsen with activity, and only proper resting can one bring it down. Dark skin complexion and the presence of anemia can often make it hard for the parents and doctors alike to recognize signs of mild cyanosis.

Q.  Which speciality doctor should I consult in case my baby has Cyanosis?

  1. You should immediately go to the emergency room at the nearest hospital. The doctor there will refer you to a neonatologist.

Q.  Why do my nails look a bit bluish or purplish in colour ?

  1. Blue or purple nails, especially the area around the base of the nails can be caused by a condition called Cyanosis. You may notice it on other parts of your body too, such as lips, palms of the hands, soles of the feet, or even earlobes.

Q.  How are Cyanosis and hypoxia related?

  1. Cyanosis is a late-stage symptom of hypoxia, where vasoconstriction of the Peripheral blood vessels or decreased haemoglobin are responsible for the bluish cast of the skin.

Q.  Why does Cyanosis occur?

  1. Cyanosis occurs due to lack of oxygen in the blood. It happens when the tissues of the body do not receive blood with the requisite levels of oxygen, for a variety of reasons.

Q.  Is Cyanosis a serious condition?

  1. Cyanosis could be considered a significantly serious condition that requires immediate medical attention.

Q.  What’s the primary difference between Peripheral and Central Cyanosis?

  1. Peripheral cyanosis is primarily caused in an individual due to low blood pressure, Raynaud’s syndrome (fingers and toes become painful and blue in cold temperatures), hypothermia, heart failure, etc. The skin turning bluey-green, affected body part feels cold to the touch are common signs of identifying whether you’re suffering from peripheral cyanosis or not. The key difference between peripheral and central cyanosis is that the former affects an individual’s hands or legs, and other external body parts like fingernails, feet, etc. and can be seen either on one side of the body or both the sides in equal proportions. The latter i.e., Central cyanosis affects the core organs of the body causing a blue-green tint across lips, tongue, and unlike peripheral, symptoms of central cyanosis don’t get better when the body part is heated up. In both forms of cyanosis, you would notice problems with the heart, lungs, or nervous system.

Q.  What is Peripheral Cyanosis?

  1. Cyanosis refers to a blue tint to the skin and mucous membranes. Peripheral Cyanosis is a condition wherein there is a bluish discoloration to your hands or feet. It is generally said to be usually caused by low oxygen levels in the red blood cells or problems getting oxygenated blood to your body. Blood that’s rich in oxygen is the bright red colour typically associated with blood. When blood has a lower level of oxygen and becomes a darker red, more blue light is reflected, making the skin appear to have a blue tint.
  1. In some cases, cold temperatures are said to cause blood vessel narrowing and lead to temporarily blue-tinged skin. Warming or massaging the blue areas should return normal blood flow and colour to the skin.

Q.  What is Central Cyanosis?

  1. Central Cyanosis is a condition that is often caused due to a circulatory or ventilatory issue that leads to poor blood oxygenation in the lungs. It generally occurs when arterial oxygen saturation drops below 85% or 75%.

Q.  What is Differential Cyanosis?

  1. It is the term used for conditions where the Cyanosis is present in certain parts and absent in others.
  • Only of lower limbs: due to patent ductus arteriosus (PDA) with reversal of shunt.
  • Only of upper limbs: due to PDA with reversal of shunt in transposition of great vessels.
  • Cyanosis of left upper and both lower limbs: due to PDA with reversal of shunt and pre-ductal coarctation of the aorta.

Q.  What is Pseudocyanosis?

  1. Pseudocyanosis is a condition that’s prevalent when a bluish tint is observed on the skin and/or mucous membranes; however, there may not be hypoxemia or Peripheral vasoconstriction.
  1. This condition is normally prevalent when there is an absence of either heart or lung disease and the skin also does not blanch under exertion of pressure.
  2. It has been found out that common metals like silver, lead or even drugs like phenothiazines, amiodarone, chloroquine hydrochloride, usually cause this condition.

Q.  Why does my tongue have a bluish or purple cast or spotting?

  1. The consumption of certain foods and beverages are normally the most common cause of a purple tongue, or spotting.
  1. If no such foods or beverages are consumed, then these causes of tongue staining with a purple or blue tint can be ruled out. This could then be a sign that the blood isn’t delivering adequate oxygen to the body’s tissues. Or, that blood with low oxygen levels, which is normally dark red, rather than bright red — is what is circulating through the arteries.
  2. The blueish tint or cast that is seen due to this condition is called cyanosis. Cyanosis can also be caused by conditions that impact the lung or heart, like coronary artery disease or chronic obstructive pulmonary disease (COPD). This blue tint may be prevalent in places other than just the tongue.
  3. The tongue can also turn bluish or purple due to low oxygen levels or an obstruction in the airways.

In situations like these, a purple or blue tongue is the sign of a medical emergency. Seeking emergency medical aid if the tongue is discoloured, appears suddenly or is even seen to be accompanied by:

  • gasping for breath
  • breathing difficulties
  • pain in the chest
  • dizziness
  • fainting

Q.  How to check for Cyanosis?

  1. Pulse oximetry, coupled with clinical symptoms can quickly diagnose Cyanosis.

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