Why are the parathyroid glands important?
Everyone has an average of four parathyroid glands, each of which is a distinct, pea-sized gland tucked around your thyroid gland. Your parathyroid glands regulate calcium levels and maintain normal levels of calcium within the blood.
In more detail, the parathyroid glands secrete parathyroid hormone, or PTH. PTH directly causes calcium to be reabsorbed in the kidneys rather than allowing it to be excreted in the urine and it also causes calcium to be released from bone. PTH also activates vitamin D, which then increases dietary calcium absorption in the gut, causes reabsorption of calcium in the kidneys and also causes bone resorption, which increases calcium release into the blood. Through these mechanisms, calcium levels within the blood are maintained at a normal level.
What is primary hyperparathyroidism?
Under normal conditions, your parathyroid glands work to keep calcium levels within the normal range. Sometimes one of your parathyroid glands becomes problematic by functioning on its own and not paying attention to what is going on in the rest of the body. When the problematic parathyroid gland works independently, more parathyroid hormone is released from it than usual and this causes your calcium levels to increase above the normal level. Your body’s normal way of telling that gland to decrease its secretion of parathyroid hormone is ignored. This results in primary hyperparathyroidism, which is when high parathyroid hormone levels cause high calcium levels, or hypercalcemia. Primary hyperparathyroidism is the most common problem related to the parathyroid glands.
What are the symptoms of hypercalcemia and primary hyperparathyroidism?
Symptoms of hypercalcemia include kidney stones, osteoporosis or loss of bone density, bone fractures and/or bone pain, abdominal discomfort including pancreatitis, nausea, and constipation, muscle discomfort, muscle weakness, joint pain, memory loss, confusion, fatigue, and depression. Unfortunately, some of these symptoms are very vague and can be associated with a variety of other causes; however, when these vague symptoms occur in conjunction with hyperparathyroidism, there is a good chance that these symptoms are a result of hypercalcemia and that the symptoms will resolve with treatment.
How is parathyroid gland disease diagnosed?
Most patients are first diagnosed with primary hyperparathyroidism when routine blood work shows an abnormally high calcium level, called hypercalcemia. The diagnosis of primary hyperparathyroidism is confirmed when further lab work shows that the parathyroid hormone (PTH) level is also high.
There are many reasons for high calcium levels, but only a couple of reasons to have high calcium levels AND high parathyroid hormone levels. This is because a high calcium level usually prevents further secretion of parathyroid hormone until the calcium level returns to normal. With continued secretion of parathyroid hormone despite high calcium levels, the problem is obviously with the parathyroid gland itself. If you have both high calcium levels and high parathyroid hormone levels, there’s a high likelihood that you have hyperparathyroidism.
What studies are needed once hyperparathyroidism is suspected?
In the setting of primary hyperparathyroidism, helpful lab work includes a calcium level, a parathyroid hormone level, a vitamin D level, an evaluation of kidney function (GFR or glomerular filtration rate from routine lab work), a 24 hour urine calcium measurement obtained by analyzing a 24 hour urine collection, and a bone density scan to evaluate for decreased bone density.
Prior to surgery, it is important to determine which one of the four parathyroid glands is abnormal. Most patients have one enlarged gland (called an adenoma), while some patients have multiple enlarged glands (called hyperplasia). Additionally, the glands are located in relatively constant locations within the neck; however, sometimes they are found in unexpected areas in the neck. For these reasons, imaging is obtained before surgery to help identify which gland is the problematic gland and to verify that the problematic gland is located within the normal areas of the neck. An ultrasound of the neck in combination with a nuclear medicine scan, called a sestamibi scan, are used to locate and identify the abnormal gland. By locating the problematic gland, surgery is more efficient and focused.
How is primary hyperparathyroidism treated?
The definitive treatment for primary hyperparathyroidism is surgery. Surgery removes the abnormal parathyroid gland through a small incision in the neck.
By removing the abnormal gland, the parathyroid hormone levels return to normal, thus allowing the calcium levels to return to normal.
What happens in parathyroid gland surgery?
Once the localizing neck ultrasound and sestamibi scans are obtained, surgery targets the abnormal parathyroid gland for removal. During surgery, a small incision in the lower part of the neck, just above the collarbones, is created. Through this incision, the diseased parathyroid gland can be identified and removed.
During surgery, the parathyroid hormone levels are drawn before and after the abnormal parathyroid gland is removed. Once the abnormal parathyroid gland has been removed, a 50% drop in the parathyroid hormone level into the normal range will occur. By verifying a sufficient drop in the parathyroid hormone level, the surgeon ensures that the abnormal gland has been removed prior to waking up the patient.
What happens after parathyroid gland surgery?
Surgery is extremely successful as a permanent cure of primary hyperparathyroidism. In most cases, patients can go home the same day following surgery. Recovery after surgery is fairly quick, with most patients returning to work and normal activities within a week after surgery. Most patients who suffered from calcium-related kidney stones will never have another stone and bone density improves over time following surgery. Many patients report an improved mood and note that they feel better overall following successful parathyroid surgery. Finally, the incision in the neck typically heals very well and becomes a very subtle, cosmetically appearing scar.