What Causes Ridges in Fingernails?

Fingernail ridges are visible lines or grooves on the nail’s surface. They can run vertically from the cuticle to the tip of the nail (known as longitudinal ridges) or horizontally across the nail (known as Beau lines). 

Most fingernail ridges are harmless, especially vertical ridges that are a natural part of aging or may develop after picking or biting your nails. However, horizontal ridges can be a sign of health concerns like vitamin deficiencies, infections, or underlying conditions. 

Your fingernails can reveal a lot about your overall health, so it's important to see a healthcare provider if ridges appear, especially when they occur with other nail changes like discoloration, pain, or thickness. 

What Do Fingernail Ridges Look Like?

Fingernail ridges are raised lines or grooves that affect one or more fingernails and may run vertically or horizontally. Vertical ridges, or longitudinal ridges, are the most common type. They run from the base of the nail (cuticle) to the tip and may be barely noticeable or more pronounced. You may feel slight, uneven bumps or roughness when you run your finger along the nail.

Horizontal ridges, or Beau lines, run across the nail's width, creating deeper, more visible grooves that may feel or appear more indented. 

In addition to fingernail ridges, you may notice other nail changes, such as: 

• Brittleness: Nails may weaken and break easily 
• Splitting: Nails may split or tear 
• Thickening: Nails may thicken or be thicker in certain areas 
• Discoloration: Nails may change color and appear yellow, brown, green, or black
• Pain: Nails or the surrounding skin may feel tender or painful 

Why Your Fingernails Can Have Ridges

Nails can develop ridges for several reasons, ranging from harmless causes like aging or nail injury to more serious concerns like nutritional deficiencies or underlying medical conditions. Understanding what causes fingernail ridges and other symptoms can help you identify what might be causing them and when to see a healthcare provider. 

Aging 

Aging can cause changes in the color, thickness, shape, texture, and growth rate of your nails. Vertical fingernail ridges are a normal part of aging and typically not a cause for concern.

As you age, there is slower cell turnover in the nail matrix—the area at the base of the nail responsible for producing new nail growth. This leads to slower nail growth and, in many cases, can cause the development of nail ridges. 

Aging can cause additional nail changes like: 

• Brittle, thinning nails that are prone to breaking 
• Color changes from transparent to dull yellow, opaque, or grayish discoloration

Physical Trauma or Injury 

Trauma or injury to the nail bed (the layer of skin underneath the fingernail) can lead to fingernail ridges. Slamming your finger in a door or habits like nail biting or picking at the cuticles causes damage to the nail bed, leading to irregular growth and the appearance of ridges.

Using gel nail polish, nail polish remover (acetone), and applying acrylic nails can also cause physical trauma from aggressive filing and the chemicals in nail glue, polish, and remover. This kind of damage may lead to fingernail ridges and other nail changes, like brittle nails, nails that crack, or redness and swelling around the cuticles.

As the nail matrix or bed heals and the nail grows, fingernail ridges typically go away. However, chronic nail biting or picking can cause scarring that leads to permanent ridges. 

Skin Conditions

Chronic inflammatory skin conditions, such as eczema and psoriasis, can affect the nails and cause fingernail ridges. Inflammation can affect the nail bed and nail matrix and change how nails grow, leading to the appearance of ridges.

Psoriasis is a chronic autoimmune condition that causes thick and inflamed patches on your skin. However, this condition can also affect your nails. Nail psoriasis develops years after psoriasis first affects the skin, causing several nail changes, including:

• Horizontal ridges on the nails
• Pitting, or deep and shallow holes on the nail 
• Changes to the shape of the nail 
• Thickening nails 
• Separation of the nail plate from the nail bed (known as onycholysis) 
• Yellow, white, or brown nails 

Eczema (atopic dermatitis) is a chronic inflammatory skin condition that causes dry, itchy skin patches. Skin inflammation can affect the nail matrix and disrupt the normal nail growth process, leading to symptoms like: 

• Fingernail ridges
• Nail pitting
  
• Yellow-brown nail discoloration
• Thickened nails 

Nail Infections 

Fungal nail infections (known as onychomycosis) can cause fingernail ridges and other visible nail changes. Although fungal infections more commonly affect the toenails, they can also affect fingernails.

Fungi or yeast can change the color, texture, and shape of the nails, causing additional symptoms such as: 

• Brittleness
• Changes in the nail shape
• Crumbling outside edges of the nail 
• Debris under the nail
• Loosened or lifting of the nail 
• Dull nail surface
• White or yellow streaks on the nail sides 
• Thickening nails
  

Nutritional Deficiencies 

Certain nutritional deficiencies can cause fingernail ridges. Ridges can develop when the body does not get enough of the vitamins and minerals it needs to support healthy nail growth. Nutritional deficiencies associated with fingernail ridges include: 

• Iron deficiency: Iron is essential for the production of red blood cells, which carry oxygen to the body's tissues. Iron deficiency can cause the nails to become thin and brittle and develop vertical ridges. Iron deficiency anemia can cause koilonychia, where the nails have a spoon-like shape, curving upward at the edges. 
• Zinc deficiency: Zinc is a trace mineral that supports many bodily functions, including skin and hair health. Zinc deficiency can cause Beau lines (white and horizontal ridges) along with hair loss and delayed wound healing.
• Biotin deficiency: Biotin is a water-soluble vitamin that supports many metabolic processes, including developing tissues and breaking down nutrients from food and converting them to energy. A biotin deficiency can lead to hair loss, skin rashes, and nail changes such as ridges and brittleness.

Underlying Medical Conditions 

Sometimes, fingernail ridges are a sign of an underlying medical condition. Certain conditions can cause systemic (bodywide) changes, including changes in the appearance of your fingernails. Conditions associated with fingernail ridges include: 

• Diabetes: Chronically high blood sugar levels can damage blood vessels and body tissues in the fingers, leading to nail problems like indentations and horizontal ridges. 
• Thyroid disease: Hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) can cause nail changes. Hypothyroidism may slow nail growth, leading to vertical ridges and thin nails. Hyperthyroidism may cause nail separation (onycholysis) and abnormally curved or brittle nails.
• Peripheral artery disease (PAD): PAD occurs when plaque builds up in the arteries that supply blood flow to the arms and legs, reducing blood flow. Lack of oxygen-rich blood flow to the hands can impair nail growth and lead to changes in nail appearance, including ridges.
• Kidney disease: Chronic kidney disease causes kidney damage, leading to waste buildup in the body. This can cause nail changes, including horizontal ridges.
• Liver disease: Liver disease, such as cirrhosis (liver damage and scarring), can affect blood flow and tissues throughout the body and may lead to nail changes, including ridges and discoloration.

When to Contact a Healthcare Provider

Most causes of fingernail ridges are harmless, but changes to the shape, texture, or color of your fingernails may be a sign of an underlying condition that requires medical attention. See a healthcare provider if you develop fingernail ridges and any of the following nail changes: 

• Discoloration, such as yellow, brown, blue, or green nails 
• Clubbed nails, enlarged fingertips, and curved nails 
• Pitting (holes or dents) 
• Nail discomfort or pain 
• Peeling nails
• White lines on the nails
  
• Thickened nails 
• Redness, warmth, or swelling of the skin and cuticles surrounding the nails 

A primary care provider (PCP) or dermatologist (a doctor with special training in diagnosing and treating conditions affecting the skin, nails, and hair) can examine your nails, review your medical history, and order diagnostic tests to determine the underlying cause of your ridges. Once they identify the reason for your ridges, they can also offer treatment options that improve the appearance and health of your nails.

How To Take Care of Your Nails

Fingernail ridges that develop from injury or trauma to the nail bed or nail matrix should go away as the nail grows out. If an underlying condition is causing fingernail ridges, addressing and treating that condition may improve the appearance and texture of your nails. 

You can also try several lifestyle changes to help reduce the appearance of fingernail ridges and achieve a smoother, more polished look. These include:

• Asking your provider about taking dietary supplements (such as iron or zinc) if you have a deficiency
• Applying protein-containing clear nail polish that aims to strengthen the nails
• Gently buffing the surface of your nails to smooth out vertical ridges
  

How To Prevent Nail Ridges

It is not always possible to prevent fingernail ridges, especially when they develop due to an underlying medical condition. Otherwise, good nail hygiene practices can promote healthy, strong nails and lower the likelihood of developing nail ridges. This includes: 

• Keep your nails clean and dry
• Avoid biting or picking your nails and cuticles 
• Wear gloves when using chemical products like cleaning supplies and performing manual work
• Limit or avoid wearing artificial (acrylic) nails and gel nail polish that can weaken and damage your nails 
• Moisturize your hands with a thick cream or moisturizer daily

A Quick Review

Fingernail ridges are common and may run vertically or horizontally on one or more of your fingernails. Most fingernail ridges are not a cause for concern and develop due to aging or physical trauma to the nail (such as biting your nails).

However, ridges can sometimes develop due to nutritional deficiencies or underlying health conditions like nail psoriasis, diabetes, or thyroid disease.

See a healthcare provider if you are concerned about your nail health or if fingernail ridges develop with other nail changes, such as discoloration or brittleness. Identifying and treating the underlying cause can improve the appearance of your nails and the quality of your nail health.