Purple toenails, a bluish or dark discoloration beneath the nail, often signal an underlying issue. While frequently benign, these changes can indicate more serious health conditions. Understanding the various factors contributing to this discoloration helps determine when medical attention is necessary.
Impact and Pressure
A frequent cause of purple toenails is a subungual hematoma, a collection of blood under the nail plate. This occurs when small blood vessels beneath the nail are damaged, leading to bleeding and discoloration.
Direct trauma, such as stubbing a toe or dropping a heavy object, can damage these blood vessels. The impact ruptures capillaries, causing blood to accumulate and create a purple or black bruise under the nail.
Repetitive pressure can also lead to subungual hematomas. Poorly fitting shoes, or activities like long-distance running or hiking, cause continuous microtrauma and gradual bleeding under the nail. This is often called “runner’s toe.” The discoloration may darken to brown or black as the blood dries. Over time, the discolored area typically grows out with the nail as new, healthy nail replaces it.
Internal Health Factors
Beyond direct injury, purple toenails can signal underlying health conditions affecting circulation or oxygen levels. Conditions impairing blood flow to the extremities can cause the skin under the nails to appear bluish or purple due to insufficient oxygenated blood.
Peripheral artery disease (PAD) involves narrowed arteries, reducing blood flow to the limbs and potentially causing bluish or purplish toe discoloration. Raynaud’s phenomenon, where blood vessels narrow in response to cold or stress, can also result in temporary blue or purple changes in toes and fingers. Certain heart or lung conditions can reduce overall oxygen delivery, leading to cyanosis, a bluish tint visible under the nails.
Some medications can contribute to purple toenails as a side effect. Anticoagulants (blood thinners) can increase bleeding under the nail, even from minor trauma, leading to hematomas. Certain chemotherapy drugs are also associated with toenail discoloration. Severe anemia can cause toenails to appear blue or purple due to a lack of oxygen-carrying hemoglobin.
When to Consult a Professional
While many purple toenails resolve on their own, certain signs warrant medical attention. Consult a healthcare professional if the discoloration appeared without known injury or trauma. This helps rule out less common but more serious causes, such as skin cancer or underlying systemic diseases.
Seek medical advice if the purple toenail is accompanied by persistent pain, swelling, or throbbing. Signs of infection, such as pus, increased redness, warmth around the nail, or red streaks, indicate a need for prompt evaluation. Consult a doctor if the discoloration is spreading, the nail detaches from the nail bed, or if other systemic symptoms like shortness of breath or dizziness occur. Individuals with pre-existing conditions, such as diabetes or circulatory disorders, should also consult a doctor for any persistent toenail discoloration due to higher complication risk.