Cortisol Testing for Cushing’s: How to Catch a Sneaky Jerk in Action

Cushing’s can behave in one of two ways.  The first kind is called “florid” Cushing’s.  In this case, the tumor is a jerk all of the time.  He is busy pumping out ACTH or cortisol (depending on his location) at all times of the day.  Since this little guy has no sense of subtly he is relatively easy to catch – pretty much any time you test your cortisol, you are going to discover he is active and therefore your cortisol is abnormally high.

The second kind of Cushing’s is called “episodic” or “cyclic.”  In episodic cases, the tumor is a real sneaky little jerk.  He only spits out hormones once in awhile and although this sounds better in many ways than the florid jerks, it is a unique kind of hell in many other ways.  Episodic tumors put their host on a hormonal roller coaster, causing episodic patients to careen between “highs” from too much cortisol and “lows” from too little.   For me, during the “highs,” when my body had too much cortisol, I was often unable to sleep at all at night, my high blood pressure was really high (often 180/100 at night), and I had “‘roid rage.”   During the “lows,” when my body had too little cortisol, I felt like I had a bad flu – I was very nauseous, my joints and skin hurt, I had a fever, and was completely exhausted around the clock.  Every Cushing’s patient has their own slightly different set of high and low symptoms, but my particular set is pretty common.    And Cushing’s patients have cycles of different lengths as well.  Some patients stay in a “high” for a few weeks at a time.  My cycles were very short and pretty predictable.  For months and months, I was high for three days and then low for three.  Like clockwork.  Stop and imagine this for a moment:  every three days, for months, you get hit with what feels just like a stomach flu.  And then not being able to sleep during the other three days.   As I got sicker, my high periods got longer and my lows shorter (and more unpleasant), but the symptoms stayed roughly the same.  But the change in symptoms as I moved from high to low was undeniable – I often could tell you the hour I started going from a high to a low.  It was very striking.

In addition to the hormonal roller coaster, the other difficult part of having episodic Cushing’s is that it can be very hard to catch the little jerk in action.  Since the tumor is not pumping out hormones all the time, if you happen to test when he is active you will find your cortisol is abnormally high.  If you happen to test when he is inactive?  Your cortisol will be normal or,  as was often the case for me, abnormally LOW.

There are two schools of thought on when to test your cortisol if you have a sneaky jerk of a tumor.  The first is to figure out your high symptoms and test when you feel high.  The second is referred to by patients as  “marathon testing” which is essentially testing every day for a few weeks.   Being a very impatient person and because I cycled between highs and lows very fast, I decided to go the marathon route.  A calendar from my last month of testing is below.  I kept track of three things:  (1) my menstrual cycle, (2) whether I felt bad (i.e., low) or good (i.e., high), and (3) what kind of test I did and the test result.  Tests with an asterisk beside them indicate the cortisol level is above the upper limit of normal.

Here is what I learned:

1.  My symptoms did not always match my labs.  Even during stretches of days where I felt “high” I could have high cortisol one day and low cortisol the next.   So, for me?  Relying just on symptoms wasn’t reliable.  I am not claiming this is the case for everyone – this is how it worked for me.

2.  There are different kinds of cortisol tests – salivary, serum, and urinary free cortisol tests (UFC).  I never had a positive salivary or midnight serum test during this period.   UFC’s were the tests that demonstrated high cortisol for me.  I know from other patients that some patients always had high salivary test results but never high UFCs.  Or some had high midnight serums but never high salivary test results.  I want to come back and write a blog post about this later, because there is too much to say about why this happens.  Stay tuned.  The main takeaway is that you should try several different kinds of tests to see where high cortisol shows up in YOUR body.

3.  ALL of my high cortisol test results occurred during days 13 and 18 of my menstrual cycle.   Although this might sound like a coincidence?  It is not.  Several smart and helpful patients explained this to me and what they said was actually supported by my own testing.  Stay tuned for a blog post on this topic as well.

4.  Regardless of how and when you test, keep track of your symptoms and your test results in a spreadsheet or calendar.  If you are going to figure out how to catch your sneaky little jerk, tracking might help you keep tabs on the little guy.  Tracking was informative because, if nothing else, I learned points #1-#3 above.  That was useful for me!  I hope it is useful to you too.