I'm an Advanced Practice Nurse with over 10 years in the ICU & OR, and I'd have to disagree w/ some of the advice you've been given. Simply put, yes you can get a very good idea of your kidney function by the simple blood test called a BMP, or a CMP. Either test will give you your BUN & creatinine level. Your creatinine level is more indicative of kidney function overall. An elevated BUN alone is usually associated w/ dehydration. A normal creatinine level is b/w 0.7 - 1.3. Generally speaking for an adult male, if you see a creatinine at 1.7 and above, you are having kidney problems. I say generally speaking b/c if you have a elderly woman for example, w/ a creatinine of 1.4, this very well may be indicative of renal (kidney) impairment. However, if you are talking about a younger adult male, specifically one who has a higher degree of muscle mass, a 1.4 may be totally normal for him. So before any health care professionals chime in and say, "1.7 is too high", what I'm saying is in my clinical experience for adult males like the ones on this site, I would start to get concerned w/ a creatinine around 1.7. Anything above that requires more extensive testing.
As far as BP goes, below you'll find the guidelines from the National Institute of Health
Normal BP
Systolic - Less than 120
And
Diastolic - Less than 80
Prehypertension
Systolic 120–139
Or
Diastolic 80–89
High blood pressure
Stage 1
Systolic 140–159
Or
Diastolic 90–99
Stage 2
Systolic 160 or higher
Or
Diastolic 100 or higher
Prehypertension is usually treated by first working on behavioral changes such as, lowering your sodium level (you want >2gms/day), increasing aerobic activity, consuming a diet high in fruits and vegetables (atleast 5 portions/day), don't smoke, and limit your alcohol intake. This doesn't mean that you wouldn't be prescribed an antihypertensive agent if your prehypertensive, but usually making the above behavioral changes can bring your BP within normal limits.
Above someone suggested Lisinopril or Benicar for elevated BP. First of all I would say, look at the standards set up today. I would not be prescribing anti-hypertensive medications for someone w/ a systolic BP in the 130's. There's no need, and its too risky. Secondly, Lisinopril absolutely can drop your pressure, and I'm one of those it happened to. My BP on a cycle was 140's over 90's, so I decided to take 5mgs of Lisinopril - considered a very low dose. Just 5mgs and my pressure dropped to the low 80's over 50's - consistently for a good 5-6 hrs, and that was just 5mgs. And consistently in my clinical practice I've seen pts drop d/t Lisinopril. Most MD's, or health-care practitioners specifically place BP limits when prescribing Lisinopril, such as do not administer if SBP <120 or diastolic <70. So stating that Lisinopril has no risk of "crashing your pressure into the 80's over 50's" is just wrong. It happened to me personally as well as many, many others.
If you do choose to use a BP medication Lisinopril is a good choice, but Benicar is not near as commonly used as a first choice antihypertensive agent. Benicar is actually used more cautiously in patients w/ renal impairment, and it many times can cause severe gastointestinal issues. Besides this it is still under patent which means there are no generics and thus the cost is much greater. There are many generics which work via the same method w/ the same results for 1/10th the cost.
The best way to accurately assess your REAL BP is to take it at the exact time every day, preferably in the morning. True hypertension is an elevated BP - consistently! Your body increases your BP during stress, working out, at work, etc., but that can be totally normal. To get an accurate assessment for your doctor or for yourself, take your BP everyday at the same time for atleast 10 days, and write it down. If its consistently within the range of being pre-hypertensive (as above) then first work at decreasing your sodium - that usually helps a lot. If your not doing any cardio, or little, increase it.
Follow the behavioral advice as above. If its consitently in the 140/85 range, I would then look into anti-hypertensive medication. Although, if you do have diabetes or know renal (kidney) impairment, then the range would be 130/80 - this is when you should be looking into ant-ihypertensives.
Elevated BP does not directly effect your liver, so I wouldn't concern myself w/ that in this respect. However, if you want to check your liver function, then yes you would check your SGOT (AST) & SGPT (ALT). As many know here, these elevate many times w/ cycles, so don't be suprised. They also increase d/t muscle breakdown, so if you check your liver function I would take off from training for several days prior to the blood test to get an accurate result.
Hope this helps!