Investigations of hypertension include tests of the kidneys, heart, central nervous system, and eyes. Kidney tests include urinalysis to assess function, renal ultrasound to examine structure, and dopplers to check for renal artery stenosis. Heart tests are ECG, chest x-ray to detect left ventricular hypertension, and echocardiogram. Central nervous system imaging includes MRI and CT scans. Additional tests measure calcium, thyroid function, lipids, cortisol to check for Cushing's, and catecholamines to rule out a pheochromocytoma. A fundus exam evaluates the eyes for signs of hypertension-related complications.
2. Kidney :
• Urinary albumin , BUN (blood urea nitrogen) and/or creatinine
to detect and monitor kidney dysfunction or to monitor the effect of
medications on the kidneys.
• Urine analysis :- to help assess kidney function .
• Renal Ultrasound :-
This will show you renal structure and may show asymmetrical kidneys or
previous renal scarring.
• Renal Dopplers :-
Renal artery stenosis is one of the causes of hypertension in the young
(fibromuscular dysplasia) and in the elderly (atherosclerotic renal artery
stenosis) .
3. • 24 hour creatinine clearance :-
This is a much more sensitive indicator of true renal function and is
especially helpful in the elderly.
• Serum renin to aldosterone ratio :-
This is a routine random blood test which is very helpful for the
screening of Conn’s syndrome. It is nice to perform this test early before
the patient is on multiple medications as it is effected by most drugs
other than calcium channel blockers.
4. • Calcium :-
to determine how much total calcium or ionized calcium is circulating in the
blood; increased activity of the parathyroid glands, which produces an increase
in serum calcium, is associated with hypertension.
• TSH (thyroid stimulating hormone) and T4 – to detect and monitor thyroid
dysfunction
• Lipid profile – to evaluate levels of total cholesterol, HDL cholesterol, LDL
cholesterol and triglycerides and assess the risk of developing atherosclerosis
• Cortisol – to detect an overproduction of cortisol that may be due to Cushing
syndrome .
• 24 hour catecholamines :-
Phaeochromocytoma is a rare but definite cause of hypertension.
5. Heart :-
• ECG & x-ray :-
To detect left ventricular hypertension
• Echocardiogram :-