Most People Ignore These Early Symptoms

• A red, purple, blue, brown, or black area underneath the nail
• Tenderness when the nail is touched
• A feeling of pressure or throbbing
• Swelling around the injured area
• In more significant injuries, partial separation of the nail from the nail bed

The discoloration can look alarming, but a traumatic bruise beneath the nail is often a minor injury and usually improves as the nail grows.

Why Does the Nail Become Dark?

The dark color usually comes from blood trapped beneath the nail plate.

Unlike a bruise on the skin, where the blood can spread into surrounding tissue, blood underneath a nail has limited room to move. It therefore remains concentrated beneath the nail and can appear dark purple, blue, or almost black.

As the nail grows, the discolored portion gradually moves toward the tip. Fingernails can take several months to completely grow out, while toenails may take even longer.

Is Swelling Always a Sign of Something Serious?

No.

A small amount of swelling or tenderness after a minor nail injury does not necessarily mean that there is a serious problem. Many small nail injuries heal without specific treatment.

However, increasing pain, significant swelling, pus, spreading redness, fever, or an obvious wound should not be ignored because these can indicate a more significant injury or infection.

What Should You Do?

For a minor injury, protecting the finger or toe and avoiding further pressure on the nail can help.

A cold pack wrapped in a cloth can be used briefly to help with pain and swelling. Keeping the area clean is also important.

Most importantly, do not try to puncture, drill, or otherwise make a hole in the nail yourselfto release trapped blood. If the pressure is severe, a healthcare professional can determine whether drainage is appropriate and perform it safely when necessary.

When Should You See a Doctor?

Medical evaluation is particularly important when:

• The pain is severe or continues getting worse.
• The nail becomes extensively dark or swollen.
• There is a deep cut around the nail.
• The nail is significantly lifted or damaged.
• You cannot move the finger or toe normally.
• You suspect a fracture.
• Pus develops around the nail.
• Redness or swelling continues to increase.
• You develop a fever.