you are sitting in front of your computer and this is the very first page
of parathyroid.com 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!
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
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.
Here is the BIG PROBLEM...
Laboratories that measure your blood calcium do NOT
correct for your age!
One 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.
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
Blood calcium levels above the normal range will
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.
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.
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".
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
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
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
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.
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.