White toenails can occur for a number of reasons such as trauma to the toe, a fungal infection or an underlying medical condition, notes Foot Health Facts. When in doubt, a consultation with a medical professional is always recommended.
Trauma is a major cause for a white toenail to appear on an otherwise healthy person, notes MDHealth. Many people associate a black toenail with trauma, but a black toenail only occurs when the blood vessels under the nail have been broken. A white toenail may appear after trauma when the blood vessels remain intact.
Fungal infections on the feet and toes is also common. A fungal infection may cause a white toenail, especially when present on the outermost layer of the nail.
People who suffer repeated trauma to the toe may experience white lines throughout the toenail. This can be taken care of by reducing the trauma to the toes.
It is normal for everyone to have white at the base of the toes. This half-moon shaped white spot is known as the lunula and is perfectly normal. The size of this spot varies from person to person.
Finally, a medical condition may cause white toenails, or white lines or spots to appear on the toenails. If all other causes of white nails have been ruled out, it may be time to see a doctor.