If you are working on getting your Cushing's diagnosis (cause all that testing IS work), if you are post-op and in recovery, or if you had your adrenal glands removed (BLA), I highly recommend a sphygmomanometer (BP cuff).
Tracking your BP and pulse can really help you get a feel for when your adrenal hormones are too high or too low. It isn't a perfect barometer, but it can definitely help. Many cyclic patients have a bit of a learning curve differentiating high
cortisol periods from low cortisol periods when they are first learning about Cushing's and starting to test. Even post-op you have
to learn what "too low" feels like, and it can be somewhat different than the "lows" you feel when you cycle before surgery.
In general, your BP (and sometimes pulse) is higher when your cortisol level is higher. This is a good time to test if you are not yet diagnosed.
In general, if your BP and pulse is lower, your cortisol level is also lower.
But, as I said, this is NOT a hard and fast rule and it is best to really get a feel for your own individual symptom sets, mixed with signs such as blood pressure and pulse, and to be proactive and use prudent judgment.
In the case of adrenal insufficiency (if you cycle hard and fast, are post op, etc), things can get really bad really fast, and I always prefer to err on the side of caution. Though too much hydrocortisone, just like high endogenous cortisol, can cause significant damage over time, a little too much cortisol at one specific time (when AI/adrenal crisis is suspected) isn't likely to do any lasting harm. Too little in that same situation can become life-threatening quickly, and it often takes your ability to think clearly and act in the process.
Sometimes people with adrenal insufficiency have what is called a paradoxical response. This means their blood pressure goes high even though their cortisol levels are plummeting, as their body tries hard to compensate and stave off adrenal crisis. It will crash eventually, possibly quickly and dangerously, so it is best to treat it early if you have reason to believe this is the case with you. In such a case, adding sufficient cortisol will actually LOWER blood pressure and stabilize the patient. I had a friend show up to the ER with a BP in the 200's/100's, was finally given 100mg solu-cortef, her AI-related symptoms resolved and her BP dropped down to around the 130's/80's. (If you don't need the extra cortisol, it will raise your BP...she obviously was desperately in need! Her body put that cortisol to immediate use and started to stabilize itself.)
Regardless, try to get a feel for what "normal" is for you. Try to pay close attention to your body so you can recognize what might signify a high, or what might signify a low. At the same time, I've noticed that AI with differing causes for me can also start with differing symptoms. I have a typical "slow decline" set and a typical "fast crash" one. I also found that the low symptoms I experienced due to taking a medication that lowerd my cortisol felt different than my natural "stress/overdoing it" lows. I got used to that too. But then this year when I added in Growth Hormone replacement, I experienced another completely different set of low symptoms! It didn't occur to me it wouldn't be like the previous medication's symptoms. As miserable as I felt, I didn't recognize the symptoms as being from low cortisol till my Endocrinologist brought it up as the likely cause! DOH! It won't always be the same, so just listen, listen, listen to that body.
Another form of Adrenal Insufficiency: If you happen to also be dealing with aldosterone (another adrenal hormone) or it's synthetic replacement, fludrocortisone, the pulse/BP differences can be a very helpful indicator of sufficient replacement dosage. Addisonians, BLAers, those with hypopituitarism, and the rare few like me who have had low aldosterone despite high cortisol levels sometimes have to balance both fludro and cortisol...and it can get tricky.
Higher BP and lower pulse suggests high aldosterone, fludrocortisone over-replacement, or too much fludro and sodium in the diet. (But fludrocortisone requires a goodly amount of salt intake to function well, so judge wisely.)
Lower BP with higher pulse suggests a need for more salt or too low of an aldosterone/fludricortisone level.
Symptoms of high and low aldo/fludro are actually quite similar. And another few points worth keeping in mind is that when it is hot outside, you are sweating/active, or you are dehydrated/losing fluids for other reasons, you may need to increase your fludro or salt intake (and fluids, too) to make up for the extra loss. Some find one works better for them than the other, and how much and which appears to be fairly individual.
*This is just informational, from patient experience. Please speak with your doctor about how and when to treat symptoms and signs.*