“Stones, bones, and groans” is a medical mnemonic describing the hallmark symptoms of hyperparathyroidism, a condition in which one or more parathyroid glands produce too much parathyroid hormone (PTH) and flood the body with calcium. The full version of the phrase, dating back decades, actually runs “stones, bones, abdominal groans, and psychic moans,” covering kidney stones, skeletal damage, gut problems, and neuropsychiatric symptoms, respectively.1PubMed Central. Vignette hyperparathyroidism: glimpse into its history The rhyme endures because it neatly captures what excess calcium does to multiple organ systems at once, and because it remains a surprisingly useful clinical shorthand despite being coined in an era when the disease looked very different than it does today.
What the Parathyroid Glands Actually Do
Most people have four parathyroid glands, each about the size of a grain of rice, sitting behind the thyroid in the neck. Their sole job is to keep blood calcium within a tight range. They do this through a feedback loop: calcium-sensing receptors on the gland cells detect how much calcium is circulating, and when levels dip, the glands release more PTH to bring calcium back up.2PubMed Central. The Calcium-Sensing Receptor and the Parathyroid: Past, Present, Future PTH raises blood calcium in two main ways: it tells the kidneys to hold onto calcium instead of excreting it, and it activates cells that break down bone, releasing stored calcium into the bloodstream.3American Journal of Physiology-Renal Physiology. Physiology and pathophysiology of the calcium-sensing receptor in the kidney
In primary hyperparathyroidism, the most common form of the disease, one or more glands develop a benign tumor (adenoma) or overgrow, and the calcium-sensing receptors on those cells stop responding properly. The gland keeps pumping out PTH even though blood calcium is already high.4PubMed Central. Epidemiology, Pathophysiology, and Genetics of Primary Hyperparathyroidism – Section: Pathophysiological Aspects of PHPT The result is a body awash in calcium, and that is where the trouble begins.
Stones: Kidney Damage From Too Much Calcium
When the kidneys are forced to filter abnormally high levels of calcium, the excess spills into the urine. That calcium-rich urine is a recipe for kidney stones. Primary hyperparathyroidism is linked to both kidney stones (nephrolithiasis) and calcium deposits within the kidney tissue itself (nephrocalcinosis), with excess urinary calcium being one of several factors driving stone formation.5PubMed Central. Renal manifestations of primary hyperparathyroidism
The stones in hyperparathyroidism tend to have a distinctive composition. Beyond the usual calcium oxalate found in most kidney stones, they often contain apatite salts, because the excess PTH can interfere with how the kidneys handle acid, creating conditions that favor apatite crystal formation.6PubMed. Kidney stones as a manifestation of hypercalcemic disorders. Hyperparathyroidism and sarcoidosis For someone who keeps forming kidney stones, especially if the stones contain apatite or if they recur despite normal hydration and diet, a blood calcium check is worth requesting. Recurrent stones are sometimes the first clue that leads to a hyperparathyroidism diagnosis.
Bones: What Chronic PTH Excess Does to the Skeleton
Bone is not a static scaffold. It is constantly being broken down and rebuilt by two types of cells working in balance: osteoblasts (builders) and osteoclasts (demolishers). PTH stimulates osteoblasts to produce a signaling molecule called RANKL, which in turn activates osteoclasts to chew through bone and release calcium.7PubMed. Parathyroid hormone induces expression and proteolytic processing of Rankl in primary murine osteoblasts In small, intermittent doses, PTH actually helps build bone, which is why a synthetic form of it is used to treat osteoporosis. But chronically elevated PTH tips the balance toward demolition. The osteoclasts outpace the osteoblasts, and bone density drops.
In severe or untreated cases, this process can escalate into osteitis fibrosa cystica, a condition where bone is replaced by fibrous tissue and fluid-filled cysts. Classic radiographic signs include “brown tumors” (focal areas of bone destruction filled with reparative tissue), a salt-and-pepper appearance of the skull on X-ray, and a “rugger jersey” spine with alternating bands of dense and porous bone in the vertebrae.8BMC Musculoskeletal Disorders. Osteitis Fibrosa Cystica and pathological fractures—the classic but neglected skeletal manifestation of primary hyperparathyroidism: a case report Osteitis fibrosa cystica used to be common but is now relatively rare in countries where routine blood panels catch high calcium early. In parts of the world without widespread screening, though, it still shows up.
Groans: The Gut Symptoms of High Calcium
The “groans” in the mnemonic refer mainly to gastrointestinal complaints. High calcium levels reduce how well the muscles in the gut wall contract, because calcium directly affects nerve and muscle signaling. The practical result is constipation, sometimes severe, and a vague sense of abdominal discomfort that patients often live with for months before anyone checks their calcium.9Journal of Clinical Gastroenterology. The Parathyroids and the Gut
More serious gut complications include nausea, loss of appetite, and in some patients, pancreatitis. The reported incidence of pancreatitis in people with primary hyperparathyroidism ranges from roughly 1.5% to 12%, likely driven by the calcium overload itself.10Journal of Clinical Gastroenterology. The Parathyroids and the Gut Peptic ulcer disease was historically included in the “groans” category as well, though the connection to hyperparathyroidism is less clear-cut in modern studies than it once seemed.
Psychic Moans: The Mental and Emotional Toll
The fourth element of the mnemonic is often the most underappreciated. Roughly a quarter of people with primary hyperparathyroidism experience neuropsychiatric symptoms, which can range from depression, anxiety, and persistent fatigue to more dramatic presentations like delirium, mania, or even psychosis in severe cases.11PubMed Central. Neuropsychiatric manifestations of primary hyperparathyroidism Cognitive difficulties are common too, including trouble concentrating, memory lapses, and a sense of mental fogginess. These complaints appear even in patients whose hyperparathyroidism is classified as “asymptomatic” based on the absence of stones or obvious bone disease.12PubMed. Cognitive deficits in primary hyperparathyroidism – what we know and what we do not know: A narrative review
The tricky part is that these symptoms are nonspecific. Depression, fatigue, and brain fog have dozens of potential causes, so few patients or doctors immediately suspect a parathyroid problem. This is one of the reasons hyperparathyroidism can simmer for years before diagnosis. If you have been dealing with persistent mental sluggishness alongside any of the other symptoms on this list, a simple blood calcium test can either rule the condition in or out.
Beyond the Mnemonic: Cardiovascular Risks
The classic rhyme does not mention the heart, but the cardiovascular consequences of hyperparathyroidism are significant. Chronically elevated PTH and calcium contribute to stiffening of artery walls, vascular calcification, and the development of atherosclerotic plaques. Calcification can develop in the inner or outer layers of the arteries, both of which narrow the vessels and reduce their elasticity.13Current Vascular Pharmacology. Hyperparathyroidism and Peripheral Arterial Disease
A large study using clinical data from patients with primary hyperparathyroidism found that rates of stroke, coronary artery disease, atrial fibrillation, and blood clots were all substantially higher in these patients compared to controls, even after adjusting for traditional risk factors like high blood pressure and diabetes.14PubMed Central. Primary Hyperparathyroidism and Cardiovascular Disease: An Association Study Using Clinical Natural Language Processing Systems and Big Data Analytics – Section: Results This does not mean that every person with mildly elevated calcium is heading for a heart attack, but it does argue for treating the disease rather than watching it indefinitely.
Why Most People Today Are “Asymptomatic”
One of the odder aspects of hyperparathyroidism in the modern era is that most cases are now caught by routine blood work before any classic symptoms develop. Automated chemistry panels flag a high calcium level, which leads to a PTH check, and the diagnosis is made in someone who feels fine or attributes their fatigue to aging or stress. The disease has evolved from a grossly symptomatic condition of full-blown stones, bones, and groans into something that is often labeled asymptomatic.15PubMed Central. Vignette hyperparathyroidism: glimpse into its history
That label deserves some skepticism. Many patients classified as asymptomatic do have subtle symptoms, particularly cognitive complaints and reduced quality of life, that only become apparent in retrospect after treatment.16PubMed. Cognitive deficits in primary hyperparathyroidism – what we know and what we do not know: A narrative review The threshold for “symptomatic” in clinical guidelines is fairly high: you need a documented kidney stone, clear osteoporosis, or very high calcium. But plenty of people fall below that threshold while still feeling genuinely unwell. The mnemonic still matters because these organ systems are still taking hits, just at a slower pace and lower intensity than in textbook cases.
A Lookalike Condition That Changes Treatment Completely
High calcium and elevated PTH usually point to primary hyperparathyroidism, but there is an important mimic: familial hypocalciuric hypercalcemia (FHH). FHH is an inherited condition where the calcium-sensing receptors throughout the body are set slightly wrong, so the parathyroid glands and kidneys behave as if normal calcium levels are too low. The result is mild, lifelong hypercalcemia that looks biochemically similar to hyperparathyroidism but is generally harmless and does not require surgery.
The key distinguishing test involves measuring how much calcium appears in the urine relative to creatinine, expressed as the calcium-to-creatinine clearance ratio (CCCR). In FHH, the kidneys hold onto calcium aggressively, so urinary calcium is low. A CCCR below about 0.01 strongly suggests FHH, while values above 0.02 point toward primary hyperparathyroidism. The gray zone between 0.01 and 0.02 is where clinical judgment and sometimes genetic testing come in.17Postgraduate Medical Journal. Urinary calcium indices in primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcaemia (FHH): which test performs best? Getting this distinction right matters enormously: operating on someone with FHH does no good, while missing hyperparathyroidism in someone who needs surgery leaves them exposed to progressive organ damage.
There is also a variant called normocalcemic primary hyperparathyroidism, where PTH is elevated but calcium levels stay within the normal range. Diagnosing this reliably is harder than it sounds. When researchers followed patients initially labeled with this condition, about three-quarters could not be confirmed after several years, raising the possibility that many had a reversible cause of elevated PTH that was missed initially.18Endocrinology and Metabolism. Normocalcemic Primary Hyperparathyroidism: Need for a Standardized Clinical Approach – Section: Diagnosis
Surgery and How Surgeons Know They Got It All
The definitive treatment for primary hyperparathyroidism is removing the overactive gland or glands. Over the past two decades, there has been a shift from traditional open neck exploration toward minimally invasive, focused surgery. A key tool enabling this shift is intraoperative PTH monitoring: because PTH has a short half-life in the blood, surgeons draw blood samples during the operation and check whether PTH levels have dropped sufficiently after the suspect gland is removed. A drop of more than 50% from the pre-incision baseline generally confirms that all the overactive tissue is out.19PubMed Central. Intraoperative Parathyroid Hormone Monitoring in the Surgical Management of Sporadic Primary Hyperparathyroidism
If the PTH does not drop enough, the surgeon knows to keep looking, because there may be a second adenoma hiding elsewhere in the neck. This real-time feedback has pushed cure rates higher. In one study comparing groups with and without intraoperative PTH monitoring, the group using monitoring achieved a cure rate of about 97.5%, compared with about 93% without it.20PubMed. Minimally invasive surgery for primary hyperparathyroidism with or without intraoperative parathyroid hormone monitoring The difference is modest in absolute terms, but for the individual patient whose second adenoma would have been missed, it is the difference between cure and persistent disease.
What Happens to Bones After Surgery
Once the source of excess PTH is removed, bone density tends to recover. Up to three-quarters of patients see improvement in bone mineral density after a successful parathyroidectomy, with younger patients and those who had more severe disease tending to benefit most.21PubMed. Changes in bone mineral density after surgical intervention for primary hyperparathyroidism Among the skeletal sites measured, the femoral neck appears to respond particularly well in patients who had osteoporosis before surgery.22PubMed. Postparathyroidectomy Bone Density Changes in Patients With Biochemically Mild Primary Hyperparathyroidism
There is a catch, though. After the overactive gland is removed and PTH levels plummet, the skeleton, which has been starved and over-resorbed for months or years, starts aggressively pulling calcium out of the blood to rebuild. This can cause a sudden and sometimes dramatic drop in blood calcium known as hungry bone syndrome. In dialysis patients undergoing parathyroidectomy for secondary hyperparathyroidism, hungry bone syndrome has been reported in a large share of cases, requiring intensive calcium and vitamin D supplementation and a longer hospital stay.23PubMed Central. Risk factors and clinical course of hungry bone syndrome after total parathyroidectomy in dialysis patients with secondary hyperparathyroidism The risk is highest in patients who had very high PTH levels and significant bone disease before surgery. Younger age and higher body weight also appear to be risk factors.24PubMed Central. Risk factors and clinical course of hungry bone syndrome after total parathyroidectomy in dialysis patients with secondary hyperparathyroidism
Secondary and Tertiary Hyperparathyroidism
Primary hyperparathyroidism starts with the gland itself going rogue. But the parathyroids can also be driven into overdrive by problems elsewhere, most commonly chronic kidney disease. Failing kidneys cannot activate vitamin D properly, which leads to poor calcium absorption from the gut and rising phosphorus levels. The parathyroid glands respond by ramping up PTH production in an attempt to compensate, a state called secondary hyperparathyroidism.25PubMed Central. Secondary Hyperparathyroidism in Chronic Kidney Disease: Pathophysiology and Management
Over time, this chronic stimulation causes the parathyroid glands to physically enlarge. The growth pattern shifts from diffuse expansion to nodular overgrowth, and the enlarged glands become progressively less responsive to the signals that should tell them to calm down.26PubMed Central. Recent advances in understanding and managing secondary hyperparathyroidism in chronic kidney disease In some patients, this process crosses a tipping point: the glands begin producing PTH autonomously, pushing calcium levels above normal even though the original kidney-driven stimulus has been addressed. That autonomous state is called tertiary hyperparathyroidism.27PubMed Central. Secondary and Tertiary Hyperparathyroidism in Chronic Kidney Disease: An Endocrine and Renal Perspective Tertiary disease is essentially the parathyroids having grown so much that they no longer follow the rules. It often requires surgery, just as primary disease does.
When Hyperparathyroidism Hits During Pregnancy
Pregnancy creates a special hazard. The placenta actively transports calcium from the mother to the developing fetus, which normally suppresses the fetal parathyroid glands. If the mother has undiagnosed hyperparathyroidism, excess maternal calcium floods the fetus, and the fetal parathyroids are suppressed even further. After delivery, when the supply of maternal calcium is cut off, the newborn’s parathyroids may be too suppressed to respond, causing dangerously low calcium in the baby (neonatal tetany). For the mother, the sudden loss of the calcium “drain” to the fetus can trigger worsening hypercalcemia or even a hypercalcemic crisis postpartum.28PubMed. Primary hyperparathyroidism in pregnancy: a diagnostic and therapeutic challenge
Making matters worse, gestational hyperparathyroidism often goes undiagnosed. By the time it is caught, many women have already endured one or more failed pregnancies.29PubMed. Primary hyperparathyroidism in pregnancy: a diagnostic and therapeutic challenge Routine prenatal labs do not always include calcium, and mild elevations can be written off as normal variation. If there is any history of kidney stones, unexplained bone loss, or recurrent pregnancy loss, checking calcium and PTH is a reasonable step.
Medical Alternatives When Surgery Is Not an Option
Not everyone can or wants to undergo surgery. For patients who are poor surgical candidates or who prefer to defer an operation, medications can help manage the disease. Cinacalcet, a drug that mimics calcium at the sensing receptor and tells the parathyroid glands to reduce PTH output, is generally the first-line option for controlling high calcium levels. For bone protection, bisphosphonates or denosumab can slow bone loss by suppressing the osteoclasts that break bone down.30PubMed Central. Management of Primary Hyperparathyroidism With Severe Hypercalcemia During the COVID-19 Pandemic These medications manage the downstream effects of hyperparathyroidism but do not cure the underlying glandular problem. Calcium levels and symptoms need ongoing monitoring, and surgery remains the only definitive fix.
In acute hypercalcemic crisis, where calcium levels spike high enough to be immediately dangerous, the initial treatment is aggressive intravenous fluids to dilute and flush out calcium, often combined with calcitonin for a rapid but temporary effect, bisphosphonates for a more sustained reduction, and sometimes glucocorticoids.31PubMed Central. Successful management of hypercalcemic crisis by continuous renal replacement therapy with regional citrate anticoagulation and surgery: a case report The goal is to stabilize the patient long enough to address the cause, which in most cases means getting to the operating room once the crisis has been controlled.
Genetic Syndromes Behind Familial Cases
Most primary hyperparathyroidism is sporadic, meaning it arises without an inherited genetic cause. But a subset of cases runs in families, and several specific gene mutations have been identified. These include mutations in MEN1 (causing multiple endocrine neoplasia type 1, which can affect the parathyroids, pituitary, and pancreas), RET (associated with multiple endocrine neoplasia type 2A), CDC73 (linked to a rare syndrome that includes parathyroid carcinoma), and mutations in the calcium-sensing receptor genes themselves.32Diagnostic Histopathology. Familial hyperparathyroidism syndromes When hyperparathyroidism shows up at an unusually young age, involves multiple glands, or recurs after apparently successful surgery, clinicians consider genetic testing to check for one of these heritable syndromes. Identifying a familial form changes surveillance not only for the patient but for their relatives, who may carry the same mutation and benefit from early screening.