discusses hyperparathyroidism, parathyroid disease, parathyroid surgery, parathyroid hormone, parathyroid cancer, parathyroid operations and mini-parathyroid surgery.

Normal Blood Calcium Levels Decrease as We Get Older

The amount of calcium in the blood changes as we mature. The highest blood calcium levels are seen in teenagers and young adults. By age 35 or 40, the blood calcium should be "in the 9's" almost all of the time. Most labs do not show normal calcium ranges according to the patients age. This causes delays in the diagnosis of hyperparathyroidism.

High blood calcium. Hypercalcemia, blood calcium, high calcium, hyperparathyroid, parathyroid.

Parathyroid Intro
Normal Function
Surgery Video
MIRP Mini Surgery
Parathyroid Pictures
Kidney Stones
Who Gets It?
Finding the Tumor
Teaching Videos
Do I Have Just One?
What Causes It?
Sestamibi Scan
Surgery Cure Rates
Frequent Questions
High Blood Calcium
Low Vitamin D
Normal Calcium Range
10 Parathyroid Rules
Symptom Cartoon
Parathyroid Cancer
Secondary Hyperpara
What Patients Say
Table of Contents
Patient Map
Dr. Norman
Become A Patient
About Us




Click to see where our patients come from!



The Calcium-Pro app will tell you what is going on!


Parathyroid blog! Great stories published several times per week!
Read our Parathyroid Blog!
Our doctors write interesting stories about patients we see every day. This is the coolest thing we do--except for the app!





Our surgeons are rated in the top 1% of all surgeons in the U.S.,
6 years in a row.

Normal calcium rangeIf you are sitting in front of your computer and this is the very first page of that you have come to, and you got here because your doctor told you that you had high blood calcium, then go to our High Blood Calcium page first. This is an important page, so come back!

Normal calcium rangeThe role of the parathyroid glands is to maintain blood calcium levels in a very small, normal range. HOWEVER, this small normal range is different for different ages. The green area on this graph shows how the normal range for blood calcium changes as we go through life. The bottom X axis is our age in years, and the vertical Y axis is the amount of calcium in the blood. Note how the blood calcium increases quite dramatically when we are teenagers and growing bone (and getting taller). At age 26 our bones are the strongest and most dense (have the most calcium in them), and from that point on, the hormone changes in our bodies causes the amount of calcium in our blood to decrease. By the time we are 35 we should have most of our calcium levels below 10.2 mg/dl. Once we are over 40, we should not have calcium levels above 10.0 or 10.1. Almost all people over 35 have calcium levels "in the 9's" almost all the time. However, almost all teenagers and young adults have calcium levels in the low 10's.

Blood calcium levels change as we age. The green area shows the normal range for blood calcium according to our age.


Here is the BIG PROBLEM...

Laboratories that measure your blood calcium do NOT correct for your age!

Normal calcium rangeOne of the most common mistakes we see while evaluating thousands of patients every year for hyperparathyroidism and high blood calcium, is that doctors are not aware that the lab is not giving a "normal range" according to that patient's age. Instead, the lab will often give a normal range for "all humans" and that normal range will go up to 10.5 or even 10.7 mg/dl. Well technically the lab is correct, this is the range for all humans, but if the patient is 55 years old, then the upper limit of normal on that patient's labs SHOULD BE 10.0 mg/dl. The lab is not giving a normal blood calcium range for YOU, it is giving a normal range for all humans of all ages. 

Normal calcium rangeWe see patients over 40 years old several times every day who have had blood calcium levels over 10.0 mg/dl for years, but their doctor thinks this is normal because the lab says it is normal to have calcium up to 10.6. This is not correct! Blood calcium levels of 10.2 to 10.5 in a person over 35 indicates they have a parathyroid tumor. These patients have been going to the doctor telling them that they feel bad, but the doctor is unaware of the diagnosis of hyperparathyroidism because their lab did not give normal ranges for blood calcium according to the patient's age.  UGH!  I'm pulling my hair out--there are so many people who are suffering from a parathyroid tumor because of the lab being lazy. This is why you should always get a copy of your own blood tests and look them over (because your doctor is probably not paying close attention!).

Blood calcium levels above  the normal range will cause problems.

Normal calcium range according to patient's ageThis next graph goes one step further and shows very clearly that patients with hyperparathyroidism have high blood calcium, which is shown in blue. Note that diagnosing a person with hyperparathyroidism who is 18 years old is very different from diagnosing a person who is 65 years old. A normal, healthy teenager will have blood calcium levels that are above 10.0, and most of the time these healthy normal teenagers have calcium levels between 10.0 and 10.7 mg/dl. A patient who is 60 years old, however, should have calcium levels "in the 9's". A calcium level of 10.5 is normal in a person who is 21 years old, but signals the presence of a parathyroid tumor in an adult over 40 years old.

Normal range for blood calcium shown in green, Hyperparathyroidism is shown in blue.

Normal calcium range according to patient's ageTeenagers with hyperparathyroidism typically have blood calcium levels between 10.9 and 12.3--it isn't subtle. For us adults over 35-40 years old, however, "frequent or persistent calcium levels above 10.1" means we are almost guaranteed to have a parathyroid tumor. As you will read below, a calcium level of 10.5 in an adult over 60 years old is more dangerous than a calcium level of 11.5 in a 20 year old. One small teaching point here... the blue area starts around age 10 because hyperparathyroidism is so rare below age 10 that it essentially doesn't exist. Remember, people of any age above 10 can get a parathyroid tumor, but the peak incidence is between the ages of 50 and 80. See our page on age for more about this. Hey folks, do us a favor, print this page and these graphs and take them to your doctor. No more than 1 doctor in 1000 understands that the labs don't correct normal ranges of blood calcium according to the patient's age. Teach your doctor, because a lot of you know more than they do (and you know who you are!). (Note: about 6% of people with hyperparathyroidism can have calcium levels in the green area, not "all" patients with hyperparathyroidism have high blood calcium).

Most adults with hyperparathyroidism have blood calcium levels only little elevated.

Normal calcium range according to patient's ageThe third and final graph in this series shows that 75% of people with primary hyperparathyroidism (and thus have a parathyroid tumor in their neck) have blood calcium levels that are just modestly elevated. Other pages of this website have different graphs that show average blood calcium and PTH for our last 20,000 patients, but here we can easily show that most parathyroid tumors increase the calcium in your blood only modestly which is shown by the purple area. Thus, most adults with hyperparathyroidism have calcium levels "in the 10's". Remember, adults over 35 or 40 should have calcium levels "in the 9's".

Normal calcium range according to patient's ageNow you see the biggest challenge we face... most people with a parathyroid tumor have only slightly or modestly elevated calcium levels and the lab is not giving normal ranges specific to the patient's age. So every day we see 4 or 5 patients who have had a parathyroid tumor for 6-8 years that has not been appreciated because their blood calcium level was not recognized as being high.

The height of the blood calcium is a very poor indicator of the severity
of hyperparathyroidism. 

Normal blood calciumThe last concept for this page is very important, and something most doctors don't understand. In most things in life, and most things in medicine for that matter, a higher number is more significant than a lower number. A cholesterol of 350 is "worse" than a cholesterol of 310, for instance. Blood calcium levels are the big exception to this rule. The person with the "worse" hyperparathyroidism is the one who has had high blood calcium the LONGEST, not the one with the HIGHEST calcium. 

Thus any doctor that is "watching" or "monitoring" your slightly high calcium to see if it goes any higher doesn't understand much about hyperparathyroidism. First, how high it is doesn't matter!  A "slightly" high calcium for a number of years will cause tremendous troubles (discussed in great detail elsewhere). Second, this doctor is hurting you, because "keeping an eye on the calcium level" means he/she is adding to the duration of the high calcium, and it is the duration (how long it has been high) that causes all the troubles. The rate of high blood pressure, breast cancer, prostate cancer, renal failure, osteoporosis, A-fib, blood clots, hair loss, kidney stones, bone pain, muscle spasms, memory loss, and heart attack are all related to the duration of calcium (in years) over 10.1 mg/dl. How high the calcium has become is a very poor indicator of the severity of primary hyperparathyroidism.

A blood calcium of 11.5 is NOT more dangerous than a blood calcium of 10.5. If your doctor is waiting for your calcium to go higher, then he/she is watching a tumor slowly destroy your body and make many of you miserable. This is not good medical care. Get the tumor out of your neck and stop watching it.

If you understand the simple concepts on this one page, you know more about hyperparathyroidism than 99% of all doctors. We have a great story about the duration of high calcium in a crabby old lady in our parathyroid blog written by Dr Doug Politz. You will enjoy it.

By the way, you do NOT need an endocrinologist if you have hyperparathyroidism. You need a surgeon. And no, your insurance company does NOT require you to see an endocrinologist before you see a surgeon... there are no insurances in the US that have that requirement--because they all know it is cheaper for you to get the tumor out than it is to monitor the calcium for 5 years before you get it out.


If you have high calcium, then you should download the CalciumPro app. Let the computer tell you what is wrong. Then you can skip those dumb scans and tests your doctor wants to do!


If you want to read more about calcium levels in the blood, how to diagnose parathyroid disease, and look at a graph of normal and high calcium levels, then go to our page on Diagnosing Parathyroid Disease


The best page of this website describes the video of Dr Norman performing a complete parathyroid operation, removing two parathyroid tumors--all in less than 13 minutes. This is a very popular video.


Dr Norman gives a 6-minute video on hyperparathyroidism. This is an award-winning video and everybody loves it.

This page was last updated 06/09/2013

  Bookmark and Share


Home ] Parathyroid Intro ] Normal Function ] Hyperparathyroidism ] Symptoms ] Surgery Video ] Diagnosis ] Treatment/Surgery ] Mini-Surgery ] MIRP Mini Surgery ] Parathyroid Pictures ] Osteoporosis ] Kidney Stones ] Who Gets It? ] Finding the Tumor ] Teaching Videos ] Do I Have Just One? ] What Causes It? ] Sestamibi Scan ] Surgery Cure Rates ] Frequent Questions ] High Blood Calcium ] Low Vitamin D ] [ Normal Calcium Range ] Diagnosis-ADVANCED ] 10 Parathyroid Rules ] Symptom Cartoon ] Sensipar ] Parathyroid Cancer ] Re-Operate ] FHH ] Secondary Hyperpara ] What Patients Say ] Table of Contents ] Patient Map ] Dr. Norman ] Become A Patient ] About Us ] is an educational service of the Norman Parathyroid Center, the world's leading parathyroid treatment center
performing about 2600 parathyroid operations annually (over 50 per week). We are part of the national "High Blood Calcium is BAD" campaign.
Get the Calcium-Pro parathyroid diagnosis app developed by our experts.

Norman Parathyroid Center  (813) 972-0000
Copyright 1996-2015  All rights reserved.  Disclaimer  |  Become our Patient  |