In nature, methane is produced by the anaerobic bacterial decomposition of vegetable matter under water (where it is sometimes called marsh gas or swamp gas). Wetlands are the major natural source of methane produced in this way.
What are the exams and tests for renal artery stenosis? Blood tests. Screening blood tests may be done as part of the general evaluation of high blood pressure and may include a complete blood count, electrolytes, kidney function tests, and a urinalysis. Imaging. Renal artery narrowing can be detected with ultrasound or computerized tomography angiography or arteriography.
1 Tests of your blood and your urine may give your doctor clues about what's causing your signs and symptoms.  Imaging tests. Imaging tests allow your doctor to visualize a kidney tumor or abnormality. Imaging tests might include ultrasound, computerized tomography (CT) scan or magnetic resonance imaging (MRI).