Because high blood calcium will cause many other health issues to develop, it is almost never appropriate for your doctor to "watch" or "observe" the high calcium. In years past, it was believed that the high calcium was dangerous only when it got to be a certain high level (like 11.0 or higher). Numerous studies over the past decade have now shown that this is not true -- that how high the calcium has become is not relevant to the development of other health problems. The height of the blood calcium is not nearly as important as how LONG it has been high (over 10.0 in an adult). It is the number of years that the calcium has been high that is important. The other health problems caused by high blood calcium (listed below) are a function of the length of time that the calcium has been high. In other words, it is how long the calcium has been high that causes the secondary health problems, not how high the calcium has become.
In the past, doctors thought that a patient with "mild" elevations in blood calcium could be watched to see if the calcium got higher. It was thought that calcium levels between 10.1 mg/dl and 11.0 mg/dl (in the 10's) could be watched, but if the calcium got higher than 11.0 then the patient would be sent for surgery and parathyroid tumor should be removed. We know know that is not correct. A calcium level of 12.0 mg/dl is not more significant than a calcium level of 10.6. A person with a calcium level of 12.0 does not have a higher chance of getting any of these problems than a patient with calcium levels of 10.6. Since time is the enemy, and the height of the calcium elevation is not really important, then any doctor who is "watching" the "mild" high calcium waiting to see if it goes to a higher level is doing the wrong thing for two reasons: 1) Time is what is important and thus watching is inherently wrong. Complications occur with time. 2) A higher calcium number does not carry any more significance and is not associated with a higher incidence of complications.
Let's take a look at an example showing that time is the problem, and even very mild high calcium over time can be very bad.
Complications that occur over time if high calcium is not treated
High Blood Calcium
Causes High Blood Pressure.
The effect of high blood calcium over time is illustrated very nicely in the next two graphs. We are looking at high blood pressure (hypertension) in people with high blood calcium. The first graph shows the number of people with high blood calcium that have high blood pressure according to how high their calcium is. The bottom x-axis of the graph is the height of the calcium from the normal range in the 9's (the blue area) into the abnormal high area above 10.0 mg/dl. Note that the blue line is flat -- people with calcium levels of 11 or 12 do not have a higher incidence of high blood pressure than people with calcium levels of 10.5. A calcium level of 12 is not more dangerous than a calcium level of 10.5. As a side note, the orange line shows the incidence of high blood pressure in the general population, showing that people with high blood calcium have a much higher chance of developing high blood pressure.
The longer the blood calcium is high, the higher the chance of high blood pressure.
The second graph shows how many people with high blood calcium have high blood pressure according to the number of years that their calcium was high. Thus the second graph is different from the first in that the first has the blood calcium levels on the bottom x-axis, and the second graph has the number of years on the x-axis. The red line shows a dramatic and continuous increase in high blood pressure as the number of years of high blood calcium increases. Thus, the longer the blood calcium is high (even a little bit high), the higher the chance of having high blood pressure. Clearly high blood calcium causes high blood pressure. Almost all people with hyperparathyroidism and high blood calcium will develop high blood pressure, and most of these people will be on 2, 3, or even 4 blood pressure medications because the blood pressure is hard to control.
A nearly identical set of graphs can be shown for the other complications of hyperparathyroidism and high blood calcium. Osteoporosis often becomes severe in patients with even mild elevations in blood calcium for several years. In fact, the high blood calcium came from the bones! The same is true for kidney stones and kidney failure. How high the calcium has become does not predict the occurrence of kidney stones or kidney failure, instead these complications occur over time even when the calcium is only a "little bit" high.
The primary teaching point of this page is that high blood calcium causes many other health problems and this occurs with time. How high the calcium has become is irrelevant. The biggest mistake doctors make is to think the height of the calcium is important and that "mild" high blood calcium can be watched until it becomes higher to some "magic" high level. How high the blood calcium has become is not important! The fact that it is even a little bit high is what is important. "Mild" high blood calcium is bad. Learn more on this topic at Parathyroid.com
Adults over 30 should have blood calcium levels "in the 9's". Calcium levels above 10.1 mg/dl are often a sign of a serious medical problem.