Purple toenails can be a cause for concern, often prompting questions. While the discoloration can sometimes be alarming, it frequently stems from common and benign issues. However, a purple toenail may also signal an underlying health condition that warrants attention.
Typical Reasons for Purple Toenails
A frequent cause of purple toenails is traumatic injury, known as a subungual hematoma. This occurs when blood vessels under the nail burst due to blunt force, such as stubbing a toe or dropping an object. Blood collects between the nail plate and nail bed, causing dark red, blue, or purple discoloration. The pooled blood’s pressure can also cause throbbing pain.
Ill-fitting footwear is another common cause of purple toenails. Tight or narrow shoes exert constant pressure, causing friction and microtrauma to the nail. This repetitive stress, especially in activities like running, can lead to small bleeds under the nail, sometimes called “runner’s toe.” Prolonged pressure can injure the nail bed and cause discoloration over time.
Health-Related Causes
Beyond common injuries, purple toenails can indicate more serious health issues. Fungal infections (onychomycosis) can cause discoloration, sometimes resulting in a grayish or purplish hue. These infections often thicken or brittle the nail. Bacterial infections may also contribute to nail color changes.
Circulatory problems, such as Peripheral Artery Disease (PAD), can change toenail color. PAD involves narrowed arteries, reducing blood flow to extremities and causing oxygen deprivation in the toenail area. Systemic conditions like Raynaud’s phenomenon, which narrows blood vessels in response to cold or stress, can temporarily restrict blood flow and turn toes blue or purple. Diabetes can also cause toenail discoloration due to impaired circulation and increased infection susceptibility.
When to Consult a Doctor
Consult a healthcare provider if a purple toenail is accompanied by:
- Persistent pain, swelling, or signs of infection (pus, spreading redness, warmth).
- Discoloration that is spreading, does not improve, or if there is numbness or coldness in the affected toe.
- Purple color appeared without clear injury, or is associated with other systemic symptoms.
- A subungual hematoma covers more than 25% of the nail area, or causes intense throbbing pain (to assess for fractures or nail bed damage).
Managing and Preventing Purple Toenails
For minor cases of purple toenails from trauma, home care is effective. Resting and elevating the foot reduces inflammation and swelling, while a cold compress alleviates pain. Keep the area clean and dry to prevent infection. If a subungual hematoma causes intense pain, a medical professional may perform trephination, making a small hole to drain trapped blood and relieve pressure. This procedure should only be done by a healthcare provider to avoid complications.
Prevention involves protecting feet from injury and ensuring proper footwear. Properly fitting shoes with enough toe room prevent pressure and friction that cause discoloration. Athletes, especially runners, should select appropriate shoes and socks to minimize microtrauma. Good foot hygiene, including keeping feet clean and dry and trimming toenails straight across, contributes to overall foot health and prevents discoloration.