What causes ridges on fingernails?

Something benign - or not so benign - may be what causes ridges on fingernails

Something benign – or not so benign – may be what causes ridges on fingernails

A ridge in the nail is a raised line. What causes ridges on fingernails? Age, for one thing. Age takes its toll on body parts, including your nails. 

As people age, ridges appear on their fingernails because the nail cells get harder, which makes it more difficult for the nail to grow properly. Vertical (up and down ridges) that run from the tip of the nail to the cuticle often appear with aging. The older a person gets, the more vertical ridges he will have on his nails. 

When a splinter hemorrhage occurs, a brownish red vertical line that is faint can be seen in the nail. A splinter hemorrhage is a subungual hemorrhage and is a collection of blood that occurs beneath the fingernail or toenail, which is initially red and then turns brown. This is a classic marker of mitral stenosis, which is a disorder of the heart valve that involves the mitral valve that separates the lower and upper chambers on the heart?s left side. Stenosis occurs when the valve is not opening completely, which restricts the flow of blood.

Horizontal ridges are another thing altogether. This type of ridge may mean that you have been experiencing sub-par nutrient absorption or suffering from malnutrition. Dehydration can also cause ridges to appear in nails. Drink more water and moisturize your nails and cuticles.    

One type of horizontal nail line is called Beau?s lines. The Mayo Clinic explains Beau?s lines can be a sign of a high fever that was caused by mumps, scarlet fever, pneumonia or measles or a circulatory disease (for example, peripheral artery disease) or diabetes that is out of control has occurred. 


When a person (including a baby) has a high fever, this can cause nail ridging because the fever cuts off blood supply to the extremities. Chemotherapy can also cause Beau?s lines. 

These horizontal lines are deeply grooved and darker than the nail. Beau?s lines can crop up if someone has a metabolic problem. When the growth of the nail is broken up due to bad health or an injury, this may cause horizontal ridges as can injury to the matrix of the nail. When there is trauma to the nail, this interferes with the production of protein and its formation and this can cause ridges. 

White stria or white lines in the nail that can be seen in the moon or growth area of the nail are usually the result of trauma. If the base of the nail, which is called the matrix, is damaged when the nail is formed, the white lines are likely to appear.  

Other conditions that cause horizontal ridges include an albumin deficiencies, which occur when a person is suffering from liver or kidney disease, severe malnutrition or is undergoing chemo. This type of ridge is called Muehrcke lines and happens because pigment formation has been interrupted.

For the CSI people, know that arsenic poisoning causes horizontal nail ridges. Aldrich-Mees? or Mees? lines are horizontal nail ridges and are discolored. This is the result of thallium or arsenic poisoning and can occur if an individual is experiencing renal failure. The ridges can also be a red flag for anemia, thyroid disease or respiratory problems. Nail ridges and dark spots or streaks on the nail are present when an individual is suffering from melanoma, which is a type of cancer. 

Sometimes, skin infections occur simultaneous with the appearance of nail ridges or pus gathering under or around the nail. When these symptoms occur concurrently with nail ridges, this could be a very dangerous situation, and medical attention must be sought. 

Adding vitamin supplements and gelatin to your diet improves the health of your nails.