Surreal illustration of a person with a kidney stone shaped shadow, representing hidden health risks.

Silent Threat: Are You Ignoring a Hidden Risk of Hyperparathyroidism?

Lena Voss in Health & Wellness July 2025 • 5 min read.

"New research reveals a surprising number of people with asymptomatic hyperparathyroidism may have undiagnosed kidney stones, potentially leading to serious complications."

Primary hyperparathyroidism (PHPT) is becoming increasingly recognized as a condition where individuals often show no obvious signs. This silent progression is largely due to advancements in modern biochemical analysis, which now routinely includes serum calcium assays. Such routine testing incidentally uncovers elevated parathyroid hormone (PTH) levels, the hallmark of PHPT, even when people feel perfectly fine.

In PHPT, the relationship between calcium and PTH shifts. Higher-than-normal calcium levels are needed to suppress PTH secretion. This hormonal imbalance leads to several downstream effects, including increased calcium reabsorption in the kidneys, accelerated bone breakdown, and increased synthesis of 1,25(OH)2D (calcitriol), which further boosts calcium absorption in the intestines. These changes collectively elevate the risk of kidney-related complications.

Both symptomatic and asymptomatic PHPT are characterized by hypercalcemia, and the kidneys and bones bear the brunt of the impact. While overt symptoms include kidney stones (nephrolithiasis), calcium deposits in the kidneys (nephrocalcinosis), and excessive calcium in the urine (hypercalciuria), a significant number of individuals remain asymptomatic. This article highlights the importance of screening for silent kidney stones in these seemingly healthy individuals.

The Hidden Prevalence: Unseen Kidney Stones in 'Asymptomatic' PHPT

Surreal illustration of a person with a kidney stone shaped shadow, representing hidden health risks.

Although PHPT is often classified as 'asymptomatic', it's crucial to recognize that kidney stones themselves cause symptoms by definition. Studies employing imaging techniques report nephrolithiasis in 7-15% of PHPT patients. Conversely, only a small fraction (2-8%) of individuals with diagnosed kidney stones are found to have PHPT. Since hypercalciuria is a major risk factor for kidney stones, it begs the question: how many 'asymptomatic' PHPT patients are silently developing kidney stones?

A recent study analyzing 124 patients with PHPT aimed to shed light on this issue. The study, conducted between October 2010 and December 2017, involved patients attending endocrine clinics. PHPT diagnosis was based on persistent hypercalcemia alongside elevated or inappropriately normal PTH levels. Researchers collected comprehensive data, including anthropometric measurements, clinical observations, and biochemical markers. Crucially, radiological investigations like X-rays, ultrasounds, and CT scans of the kidneys, ureters, and bladder (KUB) were performed at the discretion of the clinicians.

Key Finding: The study revealed that 14.5% (18/124) of patients had occult urolithiasis, meaning they had kidney stones without experiencing typical symptoms.
Imaging Modalities: CT KUB scans were the most sensitive method for detecting these silent stones, identifying 40.5% of cases. In comparison, USS KUB detected 11.5%, and X-ray KUB identified 33.4%.
Stone Location: The most common location for these stones was within the kidney itself (n = 11), followed by the pelvic ureteric junction (PUJ) and ureter (n = 5), and both the kidney and ureter (n = 2).

Interestingly, while patients 'with stones' had slightly higher adjusted calcium, PTH, and urinary calcium/creatinine ratios (UCaCr), these differences weren't statistically significant. However, a concerning finding was that renal function, measured by creatinine levels (87.9 ± 22.0 versus 74.6 ± 19.2 µmol/l; p = 0.004) and estimated glomerular filtration rate (eGFR) (71.6 ± 15.0 versus 76.8 ± 14.8 ml/min/1.73m²; p = 0.08)], was significantly worse in patients with 'stone' disease. This suggests that even silent kidney stones can contribute to declining kidney function.

Takeaway: Screen for Silent Kidney Stones to Protect Kidney Health

The findings underscore that a substantial portion (nearly 15%) of patients with PHPT may harbor silent kidney stones. This challenges the conventional classification of these individuals as truly 'asymptomatic'. The study advocates for routine renal tract imaging in all patients diagnosed with PHPT. Detecting these asymptomatic stones can influence treatment decisions, potentially leading to surgical intervention and preventing further complications. By proactively identifying and addressing silent kidney stones, healthcare providers can better preserve kidney function and improve long-term outcomes in patients with PHPT.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1177/2042018818788201, Alternate LINK

Title: Subclinical Urolithiasis In Patients With Asymptomatic Primary Hyperparathyroidism

Subject: Endocrinology, Diabetes and Metabolism

Journal: Therapeutic Advances in Endocrinology and Metabolism

Publisher: SAGE Publications

Authors: Hussam Abusahmin, John Geen, Gautam Das

Published: 2018-07-24

Everything You Need To Know

What is Primary hyperparathyroidism (PHPT), and how does it relate to the development of health problems?

Primary hyperparathyroidism (PHPT) is a condition characterized by elevated levels of parathyroid hormone (PTH) in the blood, often discovered through routine serum calcium assays. The hormonal imbalance in PHPT leads to hypercalcemia, where higher-than-normal calcium levels are needed to suppress PTH secretion. This disrupts the normal balance of calcium and PTH, leading to increased calcium reabsorption in the kidneys, accelerated bone breakdown, and increased synthesis of 1,25(OH)2D (calcitriol), which further boosts calcium absorption in the intestines. These changes collectively elevate the risk of kidney-related complications, including the formation of kidney stones and decreased renal function.

Why is it important to identify kidney stones in individuals with asymptomatic Primary hyperparathyroidism (PHPT)?

The study highlights that even though individuals with Primary hyperparathyroidism (PHPT) may not exhibit overt symptoms, a significant portion can still have kidney stones, a condition known as nephrolithiasis. The research indicates that approximately 14.5% of individuals with PHPT were found to have kidney stones despite being classified as 'asymptomatic'. This prevalence underlines the importance of considering potential kidney complications even in the absence of obvious symptoms. This is important because the presence of kidney stones, even silent ones, can impact renal function.

What are the potential health issues associated with kidney stones?

Kidney stones can cause various health issues. The silent presence of kidney stones, as observed in individuals with Primary hyperparathyroidism (PHPT), can lead to a decline in kidney function, as measured by creatinine levels and estimated glomerular filtration rate (eGFR). This reduced renal function can eventually lead to more severe kidney diseases. Furthermore, the location of kidney stones can vary, with the most common locations being within the kidney itself, followed by the pelvic ureteric junction (PUJ) and ureter. The impact of these stones on kidney health underscores the significance of timely detection and intervention.

Why is routine screening recommended for people with Primary hyperparathyroidism (PHPT)?

Routine screenings for individuals with Primary hyperparathyroidism (PHPT) are essential. The findings suggest that many patients may have kidney stones without experiencing any symptoms. Early detection of these stones through imaging techniques, such as CT KUB scans, can facilitate timely intervention. The study supports the idea of routine renal tract imaging in all PHPT patients. This proactive approach is critical for treatment decisions, including potential surgical interventions, and ultimately preventing further complications and preserving kidney function. By implementing such screening protocols, healthcare providers can significantly improve the health outcomes for individuals with PHPT.

How were kidney stones detected in the study, and what were the key findings?

The study used various imaging modalities, particularly CT KUB scans, to detect kidney stones in patients with Primary hyperparathyroidism (PHPT). CT KUB scans were the most sensitive method, identifying 40.5% of cases. Other methods included USS KUB and X-ray KUB. Although there were slight differences in certain biochemical markers between those with and without stones, the significant finding was that patients 'with stones' had notably worse renal function. The study's use of comprehensive data collection, including anthropometric measurements, clinical observations, and biochemical markers, demonstrates a thorough approach to understanding the prevalence and impact of kidney stones in asymptomatic individuals with PHPT.