Does Kidney Disease Affect Fingernails?

Chronic kidney disease (CKD) impacts an estimated 15%¹ of American adults. Many people with the condition are unaware that they have it. There are many symptoms of kidney disease, but they may not be noticeable until it reaches a severe stage. 

One symptom to watch for is changes in your fingernails, as these can appear before other clinical findings. Shifts in your fingernail color, texture, or shape don't automatically mean you have kidney disease. Still, they can indicate that your kidney function has decreased or other health issues. 

Learn more about how kidney disease and other conditions can impact your nails. 

Does kidney disease affect fingernails?

Yes, kidney disease can affect your fingernails. Your kidneys work hard to filter your blood and remove waste products. When you have CKD, your kidneys can't filter out the waste products efficiently, causing various changes throughout your body. When nitrogen waste accumulates in your body, it can damage your fingernails and toenails. 

People with kidney disease may have malnutrition because they have to limit certain nutrients in their diet, like salt. They may no longer have an appetite for foods they once enjoyed. Keratin is a protein that makes up your nails and hair, so they may be affected if you don't eat enough protein.

Vitamin deficiencies, especially among the B vitamins, can also cause changes in the texture, shape, and color of your nails. Eating a balanced, kidney-friendly diet can prevent malnutrition and vitamin deficiencies.

Finally, some people with kidney disease take medications² that can affect their fingernails. If you have noticed changes in your nails after starting a new drug, ask your doctor if it's a side effect. 

There are many possible changes to your fingernails:³ Some may be associated with kidney disease, while others may have different origins. Here are some common nail issues to look out for:

Linear depressions across the fingernail 

Also called Beau's lines,⁴ these grooves run horizontally across the fingernail, parallel to the knuckles below. Beau's lines occur when nail growth is interrupted, which can happen due to:

• Eczema

• Chemotherapy

• Nail injury

• Illnesses

• Malnutrition

If you notice Beau's lines, it may be a good idea to schedule an appointment with your doctor to determine the cause. 

Half-and-half nails

Half-and-half nails⁵ take on a white color on the bottom half and a red, brown, or pink color on the top half of the nail. They're also called Lindsay's nails. People with kidney disease commonly see half-and-half nails, and half-and-half fingernails are far more common than toenails. 

Other causes of Lindsay’s nails include:

• Zinc deficiency

• Liver disease

• Crohn’s disease

• HIV

Spoon-shaped concave nails

Concave nails,⁶ or those that look like they have a spoon-shaped dent, are also called koilonychia. Early on, the nails become flat and eventually take on a concave shape. Koilonychia can indicate other health problems. 

People with koilonychia may have an iron deficiency. Insufficient iron may be a dietary or digestive issue. For example, celiac disease prevents iron from being absorbed properly. 

Other causes of  koilonychia may include: 

• Heart disease

• Diabetes

• Lupus

• Psoriasis

• Hypothyroidism

White streaks

White streaks, also called Muehrcke's nails,⁷ are common in people with kidney disease. Muehrcke's nails are white streaks that run parallel to the knuckles of the fingernail. They form when there isn't enough blood flow to the nail bed.

Muehrcke's nails causes can include:

• Trauma to the nails

• Chemotherapy

• AIDS

• Liver disease

• Malnutrition

Interestingly, mountain climbers may also experience Muehrcke's nails. 

A white streak here and there may not be cause for concern, but multiple white spots on many nails may warrant a visit to your doctor. 

Yellow or opaque coloring

You may feel embarrassed if you have yellow or opaque nails as you may feel they’re very noticeable. There are various reasons why they can occur. 

Staining from regular nail polish use is the most common reason, especially when combining it with acetone nail polish removers. In this case, there is no actual harm to the nail, and it doesn't indicate any health problems. 

Fungal infections can also cause yellowing. This is more common for toenails than fingernails due to the humidity and stress from some shoes. 

Other causes of discolored nails can include:

• Trauma and bruising

• Jaundice

• Psoriasis

• Thyroid disease

• Liver disease

• Diabetes

Many people with chronic kidney disease have one or more of those conditions simultaneously. If you notice your nails have turned yellow, it might be time to see a doctor to determine the cause and necessary treatment. 

Brittle nails

Brittle nails⁸ are common as people get older. Weak or soft nails can also be caused by: 

• Regular manicures and nail polish removal

• Overexposure to moisture

• Anemia

• Hyperthyroidism

• Fungal infection

• Psoriasis

Brittle nails aren't necessarily associated with kidney disease. Nonetheless, if your nails have gotten weaker in recent months, ask your doctor to check for any underlying health problems. 

Pitted nails 

Nail pitting may present as shallow or deep dents in your fingernails or toenails. Pitted nails are most commonly associated with: 

• Skin disorders: Psoriasis and eczema

• Reactive arthritis and osteoarthritis

• Autoimmune diseases: Alopecia areata

Pitted nails may not indicate that you have kidney disease directly, but people with psoriasis are more likely⁹ to develop kidney disease. 

Researchers aren't quite sure how psoriasis and kidney disease are connected, but psoriasis is an autoimmune condition. These conditions cause the body's immune system to attack its own cells, increasing your odds of suffering from organ damage.

Management and treatment

The best way to manage and treat changes to your nails is to get to the bottom of the cause. If the cause is kidney disease, the right treatment plan and specific lifestyle changes may produce stronger, healthier nails. Nails can recover from many changes eventually, but some practices can make them look and feel healthier. These can also maintain your nails' appearance in the long run:

• Keeping fingernails clean

• Wearing rubber gloves when washing dishes or using cleaning products

• Using moisturizer on hands, cuticles, and nails

• Avoiding biting fingernails and picking at cuticles

• Not using harsh nail products, like acetone nail polish remover

• Avoiding pulling off hangnails (a small piece of torn skin near your nail)

Many people also turn to manicures and pedicures to keep their nails looking healthy, but this may worsen the problem if you go to an unlicensed salon. To get a license, salons must adhere to cleanliness standards to maintain the health and safety of their clients. Be sure only to visit those that have a current state license displayed. 

When should you visit a doctor?

You don't necessarily need to visit your doctor as soon as you notice a change in one nail. However, seeing changes across all or many of your fingernails or toenails may warrant an appointment. 

Visiting your doctor early can catch any issues while they’re more receptive to treatment. 

You should also see your doctor if you notice other symptoms of kidney disease, such as:

• Shortness of breath

• Chest pain

• Fatigue

• Appetite changes

• Vomiting

• Muscle cramps

• Dry skin

• High blood pressure

• Swollen feet and ankles

Many people with kidney disease don't know until it reaches a later stage. Seeing a doctor sooner rather than later can get you the treatments you need to slow the progression of kidney disease. 

The lowdown

Your nails can say a lot about your health, especially if you notice sudden changes in their texture, thickness, color, or shape. There are many reasons your nails can look different, and lots of those causes aren't severe. Still, some can be, such as kidney disease or diabetes. 

It's often better to get checked out if you’re concerned. Most chronic conditions respond better when your doctor can start treatment early. 

Even if a chronic condition isn't causing changes to your nails, your doctor may be able to help. They could prescribe treatment to make your nails look and feel better or refer you to a dermatologist for an expert opinion.