Kidney disease leaves visible marks on fingernails and toenails, and the changes are remarkably common. Studies consistently find that roughly 75 to 80 percent of people with advanced chronic kidney disease or those on hemodialysis have at least one recognizable nail abnormality, ranging from color shifts and white bands to crumbling, thickened nails.1PubMed Central. Chronic kidney disease entertained from Lindsay’s nails: A case report and literature review Some of these changes are distinctive enough to tip off a clinician before blood work confirms what is happening inside the kidneys, while others overlap with signs of liver disease, malnutrition, or simple aging.
How Common Are Nail Changes in Kidney Disease
The numbers vary depending on how closely researchers look and what stage of kidney disease they study, but the range is consistent enough to be striking. One study of 70 patients with chronic renal failure found nail abnormalities in 80 percent of them.2Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure A case-control study of end-stage renal disease (ESRD) patients who were not yet on dialysis found abnormalities in about 83 percent, compared to roughly 67 percent of age-matched controls.3International Journal of Dermatology and Venereology. The Spectrum of Nail Disorders in Patients With End-Stage Renal Disease Undergoing Conservative Treatment: A Case-Control Study Among hemodialysis patients specifically, another study reported 76 percent prevalence versus 30 percent in healthy controls.4PubMed. Nail changes in chronic renal failure patients under haemodialysis A cross-sectional study across all stages of chronic kidney disease found a somewhat lower rate of about 56 percent, with fingernails affected more often than toenails.5Journal of Onychology and Nail Surgery. Nail changes in chronic kidney disease: A cross-sectional study
That spread makes sense. Nail changes tend to become more frequent and more severe as kidney function deteriorates. Someone with early-stage kidney disease might show little or nothing, while someone who has been on hemodialysis for years could have multiple nail problems on the same hand. Fingernails are more commonly involved than toenails, probably because they grow faster and their bed is more sensitive to metabolic disruptions.
Half-and-Half Nails, the Signature Finding
If kidney disease has one calling-card nail sign, it is half-and-half nails, also called Lindsay’s nails. The nail divides into two distinct zones: the half closer to the cuticle looks white or pale, while the half near the tip turns reddish-brown, pink, or brown. A sharp line separates the two. The color does not fade when you press on the nail, which means it is embedded in the nail bed itself rather than caused by blood flow you can temporarily squeeze out.6Mayo Clinic Proceedings. Half-and-Half Nails in Chronic Kidney Disease
The distal brown band typically covers somewhere between 20 and 60 percent of the nail’s length. It can appear on a single finger, a few fingers, or all of them. Toenails occasionally show it too, though that is less common.7Mayo Clinic Proceedings. Half-and-Half Nails in Chronic Kidney Disease Estimates of how often it shows up range from about 20 to 50 percent of people with chronic kidney disease.8PubMed Central. Chronic kidney disease entertained from Lindsay’s nails: A case report and literature review In individual studies the reported rates have run from about 17 percent in ESRD patients not on dialysis to over 50 percent in long-term hemodialysis patients.9International Journal of Dermatology and Venereology. The Spectrum of Nail Disorders in Patients With End-Stage Renal Disease Undergoing Conservative Treatment: A Case-Control Study10PubMed. Nail changes in chronic renal failure patients under haemodialysis
One interesting finding: the severity of the color banding does not track with how bad the kidney numbers are. There is no correlation between Lindsay’s nails and blood urea nitrogen or creatinine levels, so you cannot judge how much kidney function someone has lost just by looking at the nail.11PubMed Central. Chronic kidney disease entertained from Lindsay’s nails: A case report and literature review The nails are a signal that something is wrong, not a meter of how wrong.
How Lindsay’s Nails Differ from Terry’s Nails
A common source of confusion, even among clinicians, is telling Lindsay’s nails apart from Terry’s nails. Terry’s nails also show a whitened nail bed with a dark band at the tip, but they are associated with liver cirrhosis and congestive heart failure rather than kidney disease. The practical distinction comes down to how much of the nail the distal band occupies. In Lindsay’s nails, the brown or pink band typically takes up 20 to 60 percent of the nail’s length. In Terry’s nails, the dark band is narrower, usually just a thin strip at the very end, with the whiteness dominating most of the nail.12The American Journal of Medicine. Systemic Diseases Revealed Through Fingernail Changes: A Report of Two Cases In practice the distinction can be tricky, especially when someone has both kidney and liver problems, but the width of the distal band is the key clue.
The Disappearing Lunula
The lunula is the pale, crescent-shaped arc at the base of the nail. In kidney disease, it often vanishes entirely. Absent lunula is one of the two most frequently documented nail findings in people with ESRD, and it has been observed in up to about 63 percent of people with chronic kidney disease in some studies.13PubMed Central. Absent lunula: An overlooked finding in chronic kidney disease Other studies have found rates in the range of 15 to 56 percent, depending on the stage of disease and whether the patients were on dialysis.14Journal of Onychology and Nail Surgery. Nail changes in chronic kidney disease: A cross-sectional study15International Journal of Dermatology and Venereology. The Spectrum of Nail Disorders in Patients With End-Stage Renal Disease Undergoing Conservative Treatment: A Case-Control Study
This finding is worth knowing because it can appear before someone starts dialysis, which means kidney disease itself, not the treatment for it, plays a role.16PubMed Central. Absent lunula: An overlooked finding in chronic kidney disease Absent lunula is not exclusive to kidney problems, though. It has also been described in people with chronic lung disease and rheumatoid arthritis. Still, when multiple nails on both hands lose their lunula, and the person has other risk factors for kidney disease, it can serve as a prompt to check kidney function.
White Lines and Bands Across the Nail
Kidney disease can produce a few different patterns of whiteness across the nails, and each points to something slightly different going on in the body.
Muehrcke’s lines are paired white bands that run horizontally across the nail, parallel to the lunula. They sit in the nail bed, not in the nail plate itself, which means they do not move as the nail grows out. If you press on the nail and the bands temporarily disappear, that confirms they are a bed phenomenon. Muehrcke’s lines are most strongly linked to low albumin levels, typically below about 2 grams per deciliter.17The American Journal of Medicine. Muehrcke’s Lines in a Patient with Nephrotic Syndrome Kidney disease causes low albumin through different pathways depending on the specific condition. Nephrotic syndrome, for instance, dumps protein into the urine. In advanced kidney failure, chronic inflammation and poor nutrition contribute. Muehrcke’s lines have been reported in roughly 7 percent of chronic renal failure patients in some studies, making them less common than half-and-half nails but more diagnostically specific.18Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure
Leukonychia, or simple white spots or patches, is more general. True leukonychia involves the nail plate itself, meaning the white spots grow out with the nail over weeks. Apparent leukonychia, by contrast, originates in the nail bed and stays put when the nail grows. The distinction matters because true leukonychia can be caused by minor trauma, while apparent leukonychia is more likely tied to a systemic problem.19PubMed Central. Leukonychia: What Can White Nails Tell Us? In kidney disease patients, white spots were reported in about 25 percent of one patient group.20Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure
Ridges, Grooves, and Shape Changes
Nails in kidney disease often look rough even when the color is normal. Longitudinal ridging, which produces fine vertical lines running from the cuticle to the tip, was seen in over 64 percent of patients in one study.21Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure While some vertical ridging happens naturally with age, the degree seen in kidney patients often goes well beyond the mild lines healthy older adults develop.
Beau’s lines are horizontal grooves or indentations that run across the nail from side to side. They mark a period when nail growth slowed or temporarily stopped, and they grow out toward the tip over time. In kidney disease, they can appear after a severe illness, a bout of dialysis-related complications, or a nutritional dip. They have been reported in around 6 to 36 percent of patients depending on the study.22Journal of Onychology and Nail Surgery. Nail changes in chronic kidney disease: A cross-sectional study23Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure They are not specific to kidney disease at all. Any major systemic stress can pause nail growth and leave a Beau’s line behind.
Koilonychia, the “spoon nail” where the nail surface becomes concave enough to hold a droplet of water, shows up in roughly 6 to 19 percent of kidney patients.24PubMed. Cutaneous changes in patients with chronic renal failure on hemodialysis25Journal of Onychology and Nail Surgery. Nail changes in chronic kidney disease: A cross-sectional study It is classically linked to iron deficiency, and kidney disease produces iron deficiency through multiple routes: reduced production of erythropoietin, blood loss during dialysis, and chronic inflammation that traps iron in storage. Copper, zinc, and protein deficits may also contribute.26PubMed. Trophic implications of altered body composition observed in or near the nails of hemodialysis patients
Splinter Hemorrhages and Other Vascular Signs
Thin, dark lines running lengthwise under the nail are called splinter hemorrhages. They look like tiny splinters trapped beneath the nail plate and represent small bleeds from the capillaries in the nail bed. One study found them in nearly 59 percent of chronic renal failure patients, while another reported them in about 36 percent of hemodialysis patients.27Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure28PubMed. Cutaneous changes in patients with chronic renal failure on hemodialysis In the general population, splinter hemorrhages are often from minor nail trauma, but they can also signal systemic conditions including infections, vasculitis, and other inflammatory disorders.29PubMed Central. Splinter hemorrhages of the nails: a systematic review of clinical features and associated conditions In kidney disease, the combination of fragile capillaries, platelet dysfunction from uremia, and the repeated mechanical stress of dialysis likely drives the high rate.
Fungal Nail Infections in Kidney Patients
Onychomycosis, a fungal infection of the nail, is disproportionately common in people with kidney disease. Estimates across studies range from about 6 to 48 percent, depending on how the diagnosis is confirmed and how advanced the kidney disease is.30International Journal of Dermatology and Venereology. The Spectrum of Nail Disorders in Patients With End-Stage Renal Disease Undergoing Conservative Treatment: A Case-Control Study31Journal of Dermatology Research and Therapy. Nail Disorders in Patients with Chronic Renal Failure The reason behind the elevated risk is an impaired immune system. Kidney failure weakens both arms of the immune response, and the nails become more vulnerable to opportunistic fungi. Conditions that often travel alongside kidney disease, such as diabetes and peripheral vascular disease, reduce blood flow to the extremities and further raise the risk.32PubMed Central. The prevalence of onychomycosis in patients with chronic renal failure undergoing dialysis: A cross-sectional study
Treating fungal nails in kidney patients is complicated. Many oral antifungal medications are processed by the kidneys, so doses need adjusting and some drugs are avoided altogether. Topical antifungals applied directly to the nail are safer from a kidney standpoint but much less effective at clearing established infections. This means kidney patients often live with chronic fungal nails that thicken, discolor, and become painful over time.
The Nutritional Thread
Several kidney-related nail changes tie back to nutritional imbalances that kidney disease either causes or worsens. Hemodialysis patients are at particular risk because the process of filtering blood through a machine can strip away water-soluble vitamins and minerals. Researchers have mapped specific nail findings to specific nutrient gaps: Beau’s lines and chronic paronychia (inflamed skin around the nail) to zinc deficiency, koilonychia to iron, copper, zinc, or protein depletion, pale nail beds to low iron, Muehrcke’s lines to low protein, splinter hemorrhages to vitamin C deficiency, and onycholysis (nail lifting off the bed) to low iron or niacin.33PubMed. Trophic implications of altered body composition observed in or near the nails of hemodialysis patients
None of these links are absolute. A Beau’s line does not prove zinc deficiency, and spoon nails do not guarantee iron is low. But taken as a group, they give a clinician visible clues about where to investigate. In a hemodialysis setting, where blood draws already happen regularly, noticing a new nail change can help guide which lab values to watch more closely.
Do Nail Changes Reverse After Transplant
One of the more encouraging pieces of evidence is that some kidney-related nail changes do improve when kidney function is restored. Studies comparing hemodialysis patients with kidney transplant recipients have found that half-and-half nails, absent lunula, splinter hemorrhages, and onycholysis all become less frequent after transplantation.34Journal of the American Academy of Dermatology. Nail disorders in hemodialysis patients and renal transplant recipients: a case-control study35American Journal of Dermatology and Venereology. Nail Changes in Hemodialysis Patients and Renal Transplant Recipients (A Case-Control Study) The improvements are not universal. Leukonychia, for instance, did not decrease after transplant in at least one study, possibly because some white nail changes become permanently embedded in the nail plate.36American Journal of Dermatology and Venereology. Nail Changes in Hemodialysis Patients and Renal Transplant Recipients (A Case-Control Study)
The reversal of Lindsay’s nails after transplant is particularly telling, because it supports the idea that whatever metabolic conditions produce the color banding are tied to ongoing kidney dysfunction rather than to permanent structural damage to the nail matrix. Once kidney function recovers, the nail gradually grows out normally from the base, and the old discolored portion eventually reaches the tip and gets trimmed away. This process can take several months given the slow rate at which nails grow.
When Nail Changes Show Up Before a Diagnosis
Some people first learn about kidney disease because a doctor or dermatologist notices their nails. Case reports describe patients who presented with Lindsay’s nails or absent lunula before any symptoms of kidney failure had appeared, and the nail findings prompted blood tests that revealed advanced disease.37PubMed Central. Chronic kidney disease entertained from Lindsay’s nails: A case report and literature review38PubMed Central. Absent lunula: An overlooked finding in chronic kidney disease Kidney disease is notoriously silent in its early and even middle stages. Most people feel fine until function drops quite low, so any external clue that prompts earlier testing is valuable.
That said, no single nail sign is enough to diagnose kidney disease on its own. Half-and-half nails have occasionally been reported in otherwise healthy people, and absent lunula can show up in other chronic illnesses. The nails are a reason to check, not a reason to diagnose. If you notice persistent, unexplained changes in your nails, particularly a two-tone color pattern, the disappearance of your lunulae, or multiple horizontal white lines, mention it to your doctor, especially if you have risk factors like high blood pressure or diabetes.
The Emotional Weight of Visible Changes
Nail changes from kidney disease are not just a medical curiosity. For many patients, visible changes to their hands and nails contribute to self-consciousness and social withdrawal. Research on the broader dermatologic effects of chronic kidney disease has noted that nail abnormalities and skin discoloration can worsen feelings of isolation, compounding the emotional burden of living with a serious chronic illness.39Journal of Heart Valve Disease. Dermatologic Manifestations in Chronic Kidney Disease Patients People on hemodialysis already spend hours tethered to a machine several times a week. Coming away with nails that look visibly abnormal adds another layer of difficulty. Nail care, including keeping nails trimmed and moisturized, using gentle nail tools, and avoiding harsh chemicals, will not fix the underlying cause but can reduce brittleness and secondary damage that make the changes look worse than they need to.
Nail Findings in Children with Kidney Disease
Most research on kidney-related nail changes focuses on adults, but children with chronic kidney disease develop skin and nail abnormalities too. A study from a tertiary care center in northern India found that skin changes were present in nearly 95 percent of pediatric kidney patients, with pallor, dry skin, and itching dominating the picture.40Oxford Academic (Clinical and Experimental Dermatology). Dermatological manifestations in children with chronic kidney disease: a study from a North Indian tertiary care institute The evidence on nail-specific changes in children is thinner than in adults, partly because pediatric chronic kidney disease is rarer and partly because children’s nails grow faster, which could make some changes less persistent. But the underlying metabolic drivers, including anemia, nutritional deficits, and uremic toxin buildup, are the same regardless of age, so clinicians watching children with kidney disease should be checking their nails as part of routine physical exams.