Parathyroid disease most commonly causes fatigue, bone thinning, kidney stones, and mood changes, though many people have no obvious symptoms at all. The disease comes in two main forms: overactive parathyroid glands (hyperparathyroidism) and underactive glands (hypoparathyroidism), and each produces a distinct set of warning signs. Because early symptoms tend to be vague, parathyroid disease is frequently discovered through routine blood work before a person ever connects their symptoms to a cause.
How Parathyroid Disease Works
Your four parathyroid glands, each about the size of a grain of rice, sit behind your thyroid in your neck. Their job is to regulate calcium levels in your blood. When one or more glands become overactive, they pump out too much parathyroid hormone, pulling calcium from your bones and raising blood calcium levels. This is primary hyperparathyroidism, by far the most common form of parathyroid disease. When the glands produce too little hormone, calcium drops too low, leading to hypoparathyroidism.
Most of the symptoms people search for relate to the overactive form. The classic medical school mnemonic is “stones, bones, groans, and psychic moans,” referring to kidney stones, bone loss, digestive problems, and cognitive or mood disturbances. In practice, these dramatic presentations are less common today because the disease is often caught earlier. Most people present with nonspecific complaints like fatigue, constipation, weakness, and muscle pain.
Fatigue and Brain Fog
Fatigue is the single most reported symptom. In one study of over 2,100 patients with primary hyperparathyroidism, 63% reported significant fatigue. Other researchers have placed the number as high as 98% in smaller groups. This is not ordinary tiredness. Patients often describe a persistent, heavy exhaustion that doesn’t improve with rest and makes daily tasks feel harder than they should.
Neuropsychiatric symptoms show up in roughly 25% of patients and can include depression, anxiety, difficulty concentrating, memory problems, and sleep disturbances. Some people describe a “brain fog” that makes it hard to follow conversations or stay organized. When researchers gave patients a standardized cognitive test before parathyroid surgery, 44% showed measurable dysfunction. After surgery, that number dropped to 22%. Less commonly, the disease can trigger more severe states like delirium or psychosis, though these are rare.
Bone Loss and Fracture Risk
Excess parathyroid hormone accelerates bone turnover, pulling minerals out faster than your body can replace them. The pattern is distinctive: bone density drops most sharply at the wrist (the distal radius), with moderate loss at the hip and relatively less at the spine. This happens because parathyroid hormone preferentially breaks down the dense outer layer of bone, called cortical bone, while partially sparing the spongy interior.
In severe or long-standing cases, imaging can reveal visible skeletal damage, including thinning of the finger bones and a characteristic “salt and pepper” appearance on skull X-rays. The good news is that bone recovery after successful surgery can be substantial. Bone density at the spine and hip typically increases 10 to 12% in the first six to twelve months after surgery, and patients who started with significant bone loss have seen gains averaging 20% over four years.
Kidney Stones and Kidney Damage
Kidney stones were once the hallmark of parathyroid disease. In the 1970s and 1980s, 40 to 60% of patients had kidney complications. Today, with earlier detection, that number has dropped to around 7% in people with mild disease, though stones remain one of the clearest red flags that prompts diagnosis.
The stones form because elevated calcium in the blood spills into the urine, where it crystallizes. Most are made of calcium oxalate, though calcium phosphate stones can also form when urine becomes slightly alkaline. Some patients with parathyroid disease have “silent” stones found only on imaging, without ever experiencing the sharp flank pain typically associated with kidney stones.
Digestive Problems
The “groans” in the classic mnemonic refer to gastrointestinal symptoms. Constipation is one of the earliest and most common complaints. Beyond that, high blood calcium stimulates acid production in the stomach, and older studies found peptic ulcers in up to 30% of people with hyperparathyroidism, compared to about 5% in the general population.
Pancreatitis is a less common but more serious complication. The incidence in parathyroid patients ranges from 1 to 12% across different studies, but the risk compared to the general population is dramatically higher: one study calculated a 28-fold increase. The mechanism involves calcium deposits forming in the tiny ducts of the pancreas, causing blockage and inflammation. Calcium also triggers a chain reaction that activates digestive enzymes prematurely, essentially causing the pancreas to start digesting itself. Nausea, vomiting, and abdominal pain that seem unrelated to diet can sometimes be traced back to undiagnosed parathyroid disease.
High Blood Pressure and Heart Effects
Between 40 and 65% of people with primary hyperparathyroidism also have high blood pressure. A large Scottish study tracking over 2,000 adults with untreated mild disease found they were nearly four times more likely to develop hypertension than the general population, even after accounting for other risk factors. The link persists after adjusting for age, weight, smoking, and other conditions.
Over time, the disease can also affect the heart’s structure and function. Patients show increased stiffness in their arteries, thickening of the heart muscle (particularly the wall between the chambers), and disrupted blood pressure patterns during sleep. They are more likely to have a history of heart failure and blood clots than matched controls. These cardiovascular effects are one of the main reasons guidelines now recommend surgery for most patients, not just those with obvious symptoms.
The Quiet Version: Normal Calcium, High Hormone
There is a form called normocalcemic hyperparathyroidism where parathyroid hormone levels are elevated but calcium levels remain within the normal range on repeated testing over at least six months. This variant is largely asymptomatic, though some patients still develop kidney stones or show early bone thinning on scans. Elevated blood pressure, blood sugar changes, and subtle neuropsychiatric symptoms have been reported, but whether these are directly caused by the condition remains unclear. Many cases are discovered incidentally when bone density scans or kidney imaging reveal problems that prompt further testing.
Symptoms of Underactive Parathyroid Glands
Hypoparathyroidism produces the opposite problem: too little parathyroid hormone causes blood calcium to drop dangerously low. The hallmark symptom is tetany, a state of involuntary muscle cramping and spasms that typically starts in the hands and feet. You might notice tingling or numbness around your lips, fingertips, and toes before full cramping sets in.
Two physical signs are closely associated with this condition. One involves twitching of the facial muscles when the nerve in front of the ear is tapped. The other is a characteristic spasm of the hand, where the fingers draw together and the wrist flexes involuntarily when a blood pressure cuff is inflated on the upper arm. Beyond muscle symptoms, low calcium can cause fatigue, dry skin, brittle nails, and in chronic cases, calcium deposits in the brain that lead to seizures or movement disorders. Hypoparathyroidism most commonly occurs as a complication of thyroid or neck surgery, though it can also develop from autoimmune causes.
How Parathyroid Disease Is Diagnosed
Diagnosis relies on blood tests measuring two values simultaneously: serum calcium and parathyroid hormone. Normal total calcium is below 10.2 mg/dL, and normal parathyroid hormone generally falls between 10 and 65 pg/mL, depending on the lab. In primary hyperparathyroidism, calcium is elevated while parathyroid hormone is either high or “inappropriately normal,” meaning the body should be suppressing it in response to high calcium but isn’t. In hypoparathyroidism, both values are low.
Because many symptoms overlap with other conditions (depression, chronic fatigue, irritable bowel syndrome, early osteoporosis), parathyroid disease often goes unrecognized for years. If you have a combination of unexplained fatigue, bone thinning, kidney stones, or mood changes, a simple calcium level on routine blood work is often the first clue. Current surgical guidelines recommend parathyroidectomy for all patients with symptoms and suggest it should be considered even for most asymptomatic patients, since surgery is more cost-effective than long-term monitoring or medication.