Your SHBG level will tell how well you hold on to your testosterone, SHBG releases a small percentage of your bound testosterone in the form of free T. Free T is to free hormone that does all the good stuff, like building muscle and providing your body with the hormones it needs to fuel your body.
The problem with measuring FT directly is the short half life of a hour or less, an hour later it can be low do to the short pulses released by the body. To get accurate FT levels we calculate our TT and SHBG to get our FT scores using a SHBG a calculator.
Your estradiol is a big one, it will largely determine how well you feel mentally whenther on TRT or not. It's used for joints and bone health and is needed for you brain function.
Your LH is secreted by the pituitary gland and picked up by the testicles to produce testosterone, if low T will also be low, however if above ranges will mean testicles are damaged and this would mean you're primary hypogonadism.
FSH is one of the reproductive hormone mainly responsible for sperm production. Hematocrit is the volume of red blood cells to the total volume of blood, sometimes when testosterone is low, red blood cell count can be low. If this is the cause high blood pressure and increased heart rate can be a direct result.