Great question! To figure out whether you might have parathyroid disease, I would want to see the actual calcium levels. If a calcium is "high-normal" but is in the truly normal range, then parathyroid disease is unlikely. Unfortunately, often what is called "high-normal" is actually just high, and that indicates likely parathyroid disease.

The question then is, what is truly normal? Normal calcium levels vary with age. Adults over about age 40 will generally have calcium levels at or below 10.0 mg/dl (or 2.5 mmol/L). If it is persistently above that, then your calcium levels are high, not high-normal. (If you are under 40 years old, then you can have calcium levels that are slightly higher. For example, a 30 year old may have calcium levels in the low 10s, which can be normal for them.) Repeatedly high calcium levels above 10.0 in someone over age 40 are almost always caused by primary hyperparathyroidism. To confirm that, we would need to also check a PTH (parathyroid hormone) level. If your calcium level is above 10.0, then you should have a PTH level checked.

If your results are consistently in the high 9s – they are normal. This where your levels should be. It is still possible to have primary hyperparathyroidism if you have these "high normal" calcium levels. To diagnose this, you need to know your PTH levels. If your calcium is in the high 9s, then your PTH levels should be in the normal range, somewhere between 20 and 70 pg/ml. If your PTH level is consistently much higher than this, then you may have primary hyperparathyroidism. This is called normocalcemic primary hyperparathyroidism. These cases are harder to diagnose, so you will want to have an expert review your labs. In these cases, I like to see all of the calcium, Vitamin D, and PTH levels before making a diagnosis.

If you are concerned about parathyroid disease, it is very important to know your calcium levels. Don't accept a comment of "it was normal" or "it's high-normal". You should request your lab reports from your physicians, so you can see the actual numbers. Calcium levels are usually found within a set of labs called “Basic Metabolic Panel” or “Comprehensive Metabolic Panel."

Because these levels can be confusing, and the lab may not give an appropriate "normal range" based on age, I have created a tool to help patients and providers interpret calcium and PTH levels. You can check it out here: [Parathyroid Diagnosis App](https://www.southwestparathyroid.com/app).