Blue fingernails are commonly caused by cyanosis, which happens when there’s a lack of oxygen in the blood. Blood lacking in oxygen has a bluish tint.
There are 2 types of cyanosis: peripheral and central. Read on to find out more about each of these, as well as what you can do to bring your fingernails back to their normal color.
Peripheral cyanosis
Peripheral cyanosis causes only the skin on your hands and feet to turn blue. It’s the result of decreased blood flow to these parts of the body only.
Cold temperatures
Peripheral cyanosis can be caused by something as simple as cold temperatures. This is because your blood vessels narrow in response to the cold, meaning less blood and oxygen are able to reach the skin.
In this case, your nails should return to their normal color once your hands and feet warm up. You can speed up this process by massaging your hands and feet or running them under warm water.
Raynaud’s phenomenon
Raynaud’s phenomenon, also known as Raynaud’s syndrome, is a condition in which blood supply to specific body parts, particularly the fingers and toes, is temporarily reduced. Sometimes, it can occur without an apparent cause. Other times, it can be caused by cold temperatures or emotional stress.
Blood clots
A blood clot is a clump of blood that forms in deep tissue or within a blood vessel. It can happen as a result of an injury or it can occur spontaneously.
If a blood clot blocks blood supply to your fingers, it can cause a blue tint to appear under your fingernails.
Central cyanosis
Central cyanosis occurs throughout the body. It causes not only your hands and feet to turn blue, but also other areas, like your lips or earlobes. It’s typically a sign of low blood oxygen levels.
Since your lungs are responsible for transporting oxygen throughout your body, lung disorders can contribute to central cyanosis. These may include:
- Pulmonary embolisms (blood clots in the lung)
- Lung infections, like pneumonia or whooping cough
- Chronic lung disorder, such as chronic obstructive pulmonary disease (COPD) or asthma
- Bronchiectasis (enlargement of parts of the airway)
- Acute respiratory distress syndrome (ARDS) or neonatal respiratory distress syndrome (NRDS)