Why Do I Have Blue Fingernails?

Cyanosis is a medical term for bluish discoloration of the skin and nails. It occurs when there is too little oxygen circulating in your blood. It's especially noticeable in areas where many blood vessels are near the skin's surface, such as the fingertips, lips, gums, earlobes, and around the eyes.

While cyanosis can sometimes occur due to exposure to cold temperatures, it is usually a symptom of an underlying condition affecting the lungs or heart. If you develop cyanosis, especially if it develops suddenly, seek prompt medical attention for diagnosis and treatment.

Types of Cyanosis 

Different types of cyanosis have distinct causes and affect specific body areas. 

Peripheral Cyanosis 

Peripheral cyanosis primarily affects your distal extremities, meaning the parts furthest away from your body's center, including the fingertips, hands, feet, and toes. It also sometimes causes the nose, earlobes, and skin around the eyes to have a blue tint.

Peripheral cyanosis often occurs after spending time in cold temperatures or due to poor circulation in these areas and is not usually serious. However, it may be an early warning sign of a heart problem if your hands and feet don't return to their normal color after warming up.

Central Cyanosis

Central cyanosis is bluish discoloration of the entire body and mucous membranes, including the lips, tongue, and inside of the mouth. It occurs when your body's blood oxygen level is below 85%—below a normal blood oxygen level of 95-100%.

Heart and lung diseases can cause central cyanosis. It can also occur in people with abnormal hemoglobin, the protein in red blood cells that carries oxygen.

Perioral Cyanosis 

Perioral, or circumoral, cyanosis is blue-grey discoloration around the mouth. It is most common in newborns shortly after birth and in young children when spending time in cold weather or swimming in cold water. It usually resolves quickly.

Raynaud's Syndrome

This condition—also called Raynaud's disease or Raynaud's phenomenon—affects the small blood vessels (arteries) in your arms and legs. Triggers like cold temperatures and stress restrict blood flow to your hands and feet, causing your fingers and toes to become white and numb.

Symptoms usually last a few minutes to a few hours, but severe attacks can last several days. This is rare.

Acrocyanosis 

Acrocyanosis is a form of cyanosis that causes both hands and/or feet to be persistently blue-tinted and cold. It occurs when small blood vessels in the skin spasm, usually in response to emotional stress or exposure to cold temperatures.

With acrocyanosis, your hands and feet may also sweat profusely and swell.

Symptoms 

Cyanosis is a medical term describing bluish discoloration of the skin and mucous membranes, the soft tissues that line the body's organs and canals (e.g., nose, mouth). It is a symptom with many possible causes and often a sign that your blood does not have enough oxygen.

Cyanosis can look different and be more challenging to detect in people with darker skin tones. Discoloration around the lips and tongue may appear gray or white in people with darker skin, and the bluish tinge may be more visible on the palms of the hands, soles of the feet, nail beds, and skin around the eyes.

What Causes Cyanosis? 

Cyanosis typically occurs due to low levels of oxygen circulating in the blood. Blood normally appears red because red blood cells contain a protein called hemoglobin, which picks up oxygen in the lungs and delivers it to the body's tissues and organs. Too little oxygen can make blood appear darker with a bluish-purple hue. This is what causes bluish-tinted skin in people with cyanosis.

You may notice that the blood in your veins close to your skin appears blue. This is normal because veins carry deoxygenated blood back to the heart. When your skin takes on a bluish tint, it may signal a problem with your body's ability to deliver oxygenated blood to your body's tissues.  

Many conditions can cause insufficient oxygen blood oxygen levels, including respiratory conditions (affecting the lungs), cardiovascular conditions (affecting the heart), and conditions affecting the central nervous system (brain and spinal cord). Common causes of cyanosis include:

• Chronic obstructive pulmonary disease, or COPD (a group of chronic lung diseases that limit airflow to the lungs) 
• Interstitial lung disease (a group of conditions that cause lung scarring)
• Pulmonary embolism (blood clot in the lungs) 
  
• Congenital heart problems (present at birth)
• Cardiac arrest (sudden loss of heart function)  
  
• Prolonged seizures
  
• Pneumonia
• Asthma 
  
• Suffocation 
  

Cyanosis can also be caused by an overdose of certain drugs (e.g., benzodiazepines, narcotics, sedatives), toxin poisoning (e.g., cyanide), or environmental factors like high altitudes and exposure to cold temperatures.

Risk Factors

Anyone can develop cyanosis, but the risk is highest in people with heart and lung diseases. If you have a heart or lung disease, following your treatment plan is important for slowing or preventing disease progression or complications. You can lower your risk of cyanosis by:

• Managing underlying conditions and following your treatment plan
• Avoiding smoking 
• Avoiding extreme cold 
• Staying physically active
• Maintaining healthy blood pressure 
• Keeping your cholesterol levels within healthy ranges 

How Is Cyanosis Diagnosed?  

Cyanosis is not a diagnosis. It's a symptom of an underlying condition. When you have cyanosis, your healthcare provider will consider your medical history and symptoms and perform a physical examination to identify the underlying cause.

During your visit with a healthcare provider, they may ask questions like:

• When did you first notice a bluish appearance on your skin?
• Was it sudden or gradual? 
• Have you had recent exposure to cold temperatures or spent time at high altitudes? 
• Do you have other symptoms, such as difficulty breathing, cough, or chest pain?
  

Your healthcare provider will examine your body to look for signs of cyanosis, especially around your eyes, fingernails, toenails, lips, and mouth. They may check your feet, legs, and ankles for signs of swelling. 

Diagnostic Testing

Your healthcare provider may order diagnostic tests to determine what's causing cyanosis, including:

• Pulse oximetry: Measures blood oxygen levels with a small device that clips onto your fingertip
• Arterial blood gas (ABG) analysis: A blood test that involves taking a blood sample from an artery in your wrist, arm, or groin to measure oxygen, carbon dioxide, and acid-base (pH) balance in your blood
• Complete blood count (CBC): A blood test that measures different parts of your blood, including red blood cells and hemoglobin
• Chest X-ray: An imaging test that visualizes your lungs, heart, ribs, diaphragm, and large arteries in your chest to look for abnormalities 
• Electrocardiogram (ECG or EKG): A noninvasive test that involves placing electrodes on your arms, legs, and chest to measure and record your heart's electrical activity
• Echocardiogram: An ultrasound that uses sound waves to create images of your heart and assess its structure and function

Treatment

Oxygen therapy is a first-line treatment for cyanosis. Supplemental oxygen helps improve blood oxygen levels to ensure your body's organs and tissues get enough oxygen to function properly.

Depending on the severity of your symptoms, you may receive oxygen therapy through a cannula (tube) in your nose or require a ventilator to help you breathe.

Additional treatments for cyanosis depend on the underlying cause. For example:

• Pneumonia treatments may include antibiotics or antiviral medications.
• COPD requires ongoing management and treatment that may include bronchodilators to keep your airways open and make breathing easier or pulmonary rehabilitation to improve your lung function and quality of life.
• Treatments for heart failure may include medications to relax your heart rate, remove extra fluid from your body, or surgery to install a pacemaker or mechanical heart pump to improve your heart's function.

Prevention

It is not always possible to prevent cyanosis, especially in cases where the underlying cause is congenital (e.g., congenital heart disease)—a condition you are born with. However, certain lifestyle habits may help lower your risk of cyanosis, including the following:

• Avoid smoking: Smoking can damage your heart and lungs and reduce the lungs' ability to absorb oxygen. Avoiding smoking and exposure to secondhand smoke can help lower your risk of cyanosis associated with lung conditions like COPD.
• Dress for the weather: If you spend time in cold temperatures, dress warmly to prevent blood vessel constriction and maintain proper blood flow to your arms, legs, hands, and feet. This may include wearing mittens or gloves, thick socks and boots, and a warm winter jacket.
• Manage underlying conditions: If you have a heart or lung condition associated with cyanosis, follow your treatment plan and see your healthcare provider regularly to control symptoms and lower your risk of cyanosis and other complications.
• Make heart-healthy choices: Eating a healthy, balanced diet low in processed foods and engaging in regular physical activity can help protect your cardiovascular health.

Complications 

If left untreated, cyanosis can lead to serious health problems due to prolonged oxygen deprivation in your body's tissues and organs. Possible complications include:

• Organ damage: Prolonged oxygen deprivation can damage your body's vital organs, including your heart, lungs, brain, and kidneys. 
• Heart failure: Chronic (long-term) oxygen deficiency can weaken your heart muscle and lead to heart failure.
• Respiratory failure: This occurs when your lungs do not work properly and cannot deliver sufficient oxygen to the blood.
• Stroke: When your brain does not get sufficient oxygen supply, a stroke can occur, which can lead to long-term brain damage or death.
  

A Quick Review

Cyanosis describes a bluish discoloration of the skin and mucous membranes (lining of the body's organs and canals such as the nose and mouth) due to insufficient blood oxygen levels. There are many possible causes of cyanosis, ranging from minor acute causes like exposure to cold temperatures to more serious, chronic conditions such as heart and lung diseases.

Seek prompt medical attention if you notice signs of cyanosis in yourself or someone else. Early diagnosis and treatment of the root cause is essential for preventing complications.