Hyperparathyroidism is a hormonal problem that can develop at any age, but occurs most commonly in postmenopausal women (2% of older women and 1% of older men).
Hyperparathyroidism develops because of excessive secretion of parathyroid hormone (PTH), an important factor in calcium metabolism. It can lead to high PTH levels, high calcium levels, and a wide range of symptoms.
Parathyroid gland anatomy:
Most people are born with four parathyroid glands, though having an extra 5th parathyroid gland is not all that uncommon. Parathyroid glands are located in the neck, generally behind the thyroid gland, but can be found in unusual locations such as the carotid sheath, thymus, chest, or behind your esophagus.
Hyperparathyroidism: What causes high calcium or high PTH levels?
Primary Hyperparathyroidism
When an abnormal parathyroid gland ‘goes rogue’ and stops responding to normal signals from the body, it tells the body (unnecessarily) that it needs more calcium. Calcium is then leached from the bones (a cause of osteoporosis) and intestines, and can be deposited in the kidneys (leading to kidney stones) or other areas of the body. A build-up of too much calcium in the bloodstream can be either asymptomatic or can lead to a variety of symptoms.
Some patients have with a parathyroid tumor have normocalcemic hyperparathyroidism where the calcium level is normal but the PTH is high. Other patients may have high calcium but high-normal or normal PTH levels. Assuming that there are no other causes of high calcium or high PTH, these patients ALL have primary hyperparathyroidism that should generally be treated.
The cause of overactive parathyroids in 1% of patients is inheritance of a gene abnormality from one parent. The cause of a parathyroid tumor in the other 99% of patients is usually unknown, although radiation therapy to the face or neck can be a factor in causing a single parathyroid tumor.
Secondary Hyperparathyroidism
Secondary hyperparathyroidism is when a disease unrelated to your parathyroids causes all of your parathyroid glands to become enlarged and overactive. The most common cause is kidney failure, which at least in the beginning, leads to lower levels of calcium in the bloodstream that stimulates the parathyroid glands.
Prolonged vitamin D deficiency is the second most common of secondary hyperparathyroidism, followed by gastrointestinal malabsorption (such as after a gastric bypass procedure).
Tertiary Hyperparathyroidism
Tertiary hyperparathyroidism is when a patient that previously had secondary hyperparathyroidism now develops primary hyperparathyroidism, ie. A kidney failure patient gets a kidney transplant and some years later is diagnosed with primary hyperparathyroidism (when their new kidney is still working).
If it is true tertiary hyperparathyroidism, then the statistics are the same as primary hyperparathyroidism, ie most people have a single overactive parathyroid gland. If however, the secondary hyperparathyroidism was never ‘cured’ and then patient still has some renal insufficiency, then these patients likely have disease in all four of their parathyroid glands.
Parathyroid cancer
Parathyroid cancer is a rare cause of primary hyperparathyroidism. It is very difficult to make a parathyroid cancer diagnosis before surgery. Typically (but not always), patients will have very high calcium and very high PTH levels.
During parathyroid surgery, the parathyroid tumor is usually hard and stuck to the surrounding tissues and thyroid gland. Parathyroid cancer survival is generally very good since the tumor is very slow-growing, but since it can come back, patients may need re-operations in the future.
Signs and Symptoms of Hyperparathyroidism (and Hypercalcemia)
Hyperparathyroidism (or hypercalcemia) can be asymptomatic, can cause mild symptoms, or in rare cases severe symptoms. The most easily recognized and curable primary hyperparathyroidism / hypercalcemia symptoms are osteoporosis and kidney stones.
Other common and more nonspecific symptoms of either high calcium or high PTH are listed below:
Nervous system
- Mood swings
- Depression
- Forgetfulness
- Irritable
- Concentration problems
- Fatigue
- Decreased sexual desire or impotence
Kidney/Urinary
- Kidney Stones
- Nocturia (going to the bathroom a lot at night)
- Worsening kidney function
Digestive system
- Stomach or duodenal ulcer
- GERD (reflux)
- Pancreatitis
- Abdominal pain
- Constipation
Diagnosis of Primary Hyperparathyroidism (and secondary and tertiary hyperparathyroidism)
Since hyperparthyroidism is a hormonal problem, a diagnosis is made by measuring the hormone (ie, calcium and PTH) levels in your body.
Your physician will order, at a minimum, the following blood tests if testing for parathyroid disease:
- Calcium
- PTH (parathyroid hormone)
- Vitamin D 25-OH and vitamin D 1,25-hydroxy
- Creatinine
Once a diagnosis of primary hyperparathyroidism has been made and a surgeon is evaluating you for parathyroid surgery, parathyroid Imaging will be performed: this may include a parathyroid ultrasound, 3D parathyroid CT scan, or less commonly a Sestamibi scan. A specialty endocrine surgeon that performs a lot of parathyroid surgery will do their own parathyroid ultrasound in the office, and only order additional testing if they cannot find a single, enlarged parathyroid gland on their clinic ultrasound. Other tests your primary doctor or parathyroid endocrinologist may order include:
- DEXA Bone Scan
- 24-hour Urinary calcium
- Abdominal CT (to look for kidney stones)
Many clinicians do not look for parathyroid disease when looking for what causes mildly elevated calcium levels (hypercalcemia) in a patient or complaints such as fatigue, forgetfulness and concentration problems, depression/anxiety, kidney stones or disease, osteoporosis, constipation, stomach ulcers, or sexual dysfunction to name a few. Additionally, clinicians may not refer many patients for an easy minimally invasive surgical treatment that could cure them of their parathyroid disease and prevent complications if they think the parathyroid disease is “mild” (though it really isn’t).
Treatment of primary hyperparathyroidism (and secondary and tertiary hyperparathyroidism): Parathyroid Surgery
The only cure for hyperparathyroidism is parathyroid surgery by surgical removal of one or more parathyroid tumors (parathyroidectomy).
During parathyroid surgery, the number of parathyroid glands removed will be determined by measuring parathyroid hormone (PTH) in the blood during the operation. Most parathyroid surgery is minimally invasive (small incision.)
Some of the benefits to having parathyroid surgery include:
- Improved bone density and decreased risk of bone fractures (stabilization of osteoporosis)
- Improved quality of life
- Lower risk of kidney stones (up to 90 percent of patients do not develop any new stones)
- Decreased risk of premature death
- Disappearance or improvement of symptoms
After Surgery
There is the potential to fix and/or improve all symptoms of parathyroid disease. However, because many symptoms of hyperparathyroidism or hypercalcemia are vague and nonspecific, it is difficult to tell which symptoms are actually caused by the parathyroid tumor and which are unrelated
Most people will not have to take any medication after parathyroid surgery. There are occasional patients who have very high calcium levels for a long time before they undergo parathyroid tumor removal that will need temporary over the counter calcium supplementation.
Patients that have three or 3 ½ parathyroid glands removed due to a familial syndrome or sporadic 4-gland hyperplasia have a higher risk for temporary calcium and/or vitamin D replacement.
You will return for a post-op visit two to three weeks after your parathyroid surgery and again about 6 months later if you live locally; everyone will have repeat blood tests at this time. For all patients, we monitor your calcium, parathyroid hormone, and vitamin D levels on a yearly basis which can be arranged through our office or with your local physician and have the results sent to our office.
It is rare, but published recurrence rates at 10 years after successful parathyroid surgery are in the range of three to five percent. This is why we monitor your blood tests on a yearly basis.