Blue nail beds can be cause for concern — read on to understand why

Published: January 12, 2023 | Updated: March 9, 2023

Fingernails are good for scratching itches, but they are also a window into your health. If the skin under your fingernails has a blue or purple tinge, you might need to see a health care provider or a heart specialist.

Why are my nails blue?

The medical term for blue nail beds is cyanosis. Cyanosis can occur when there is not enough oxygen circulating in the bloodstream, or circulation is poor. Oxygenated blood is red, while blood depleted of oxygen has a blue hue.

What causes blue nails?

There are several reasons your nails could be blue, including heart conditions. Sometimes a heart murmur will cause blue nail beds. When a health-care provider listens to your heart and hears a certain swooshing sound, it’s an indication that the blood is flowing through the heart abnormally.

Heart murmurs can be innocent, or harmless. But murmurs also can be an indication of a structural heart condition such as a hole between two or more of the heart’s chambers — atrial septal defect or ventricular septal defect. While this defect is present at birth, patients can grow into middle age with little or no symptoms. Many aren’t even aware they have the condition.

Other causes of heart murmurs include:

• Anemia affecting the thickness of the blood and blood flow
• Carcinoid heart disease, a slow-growing tumor that can affect the heart’s valves
• Endocarditis, an infection that harms heart valves
• A faulty heart valve that isn’t closing all the way or is stiff, allowing blood to flow in the wrong direction
• Hyperthyroidism (an overactive thyroid) resulting in a rapid heartbeat and a murmur
• Hypertrophic cardiomyopathy, which makes your heart muscle thicker and stiffer

Another cause of cyanosis could be cold temperatures that can make blood vessels constrict, resulting in fingers and toes taking on a blue tint.

“This will go away when you warm up,” said Tara U. Mudd, APRN, nurse practitioner with Norton Heart & Vascular Institute. “Numbness and tingling when you’re cold is common, and as long as it stops when you go inside or get warm, it’s not a concern.”

When should I see a doctor?

“If you have blue nails, call your health care provider,” Tara said. “Evaluation may include using a device called a pulse oximeter, which measures the amount of oxygen in your blood. Your provider may use this data to help diagnose the underlying cause of your cyanosis and recommend treatment options.”

If your blue nail beds are caused by a serious heart issue, your physician may refer you to the Norton Heart & Vascular Institute Structural Heart Program, which brings together the talents of cardiothoracic surgeons, interventional cardiologists and imaging cardiologists to one location on the Norton Audubon Hospital campus. With the input and viewpoints of many specialties, each patient gets a customized treatment plan.