What Could Dirty, Dark, or Unusual-Looking Nails Be Telling You?

What About Nail Biting?

Nail biting is extremely common.

For some people, it's simply a habit. For others, it may occur more frequently during periods of stress, boredom, concentration, or nervousness.

Repeated nail biting can damage the nail and surrounding skin.

It can also create tiny breaks in the skin around the fingers, potentially increasing the chance of irritation or infection.

But it would be inappropriate to look at someone's bitten nails and assume that person is anxious or stressed.

A habit can have many causes, and a person's nails don't provide enough information to determine what's happening psychologically.

The Skin Around the Nails Matters Too

Sometimes the most useful clue isn't the nail itself.

Look at the surrounding skin.

Redness, swelling, tenderness, warmth, or drainage around a nail can indicate inflammation or infection.

A condition called paronychia, for example, involves inflammation or infection of the tissue around the nail.

It can develop after minor trauma, nail biting, picking at the cuticle, manicures, or repeated exposure to water and irritants.

A mild case may improve with appropriate care, but increasing pain, swelling, pus, spreading redness, or fever warrants medical attention.

What Do White Spots Mean?

White spots on fingernails are often blamed on calcium deficiency.

That's usually an oversimplification.

Small white spots commonly occur because of minor trauma to the nail as it grows. You may not even remember injuring the nail.

They generally grow out with the nail over time.

Persistent or widespread changes, however, can have other causes.

Again, the lesson is that one nail feature rarely tells the whole story.

Can Nails Reveal Nutritional Problems?

Certain nutritional deficiencies can affect the nails.

For example, severe iron deficiency may sometimes be associated with changes in nail shape or appearance.