What is the most likely cause of increased creatinine in a patient with a recent increase in blood pressure and renal function tests?

An increase in creatinine levels, particularly in the context of recently elevated blood pressure and changes in renal function tests, often suggests a decrease in kidney perfusion or damage to the kidneys. Bilateral renal artery stenosis can lead to ischemia of the renal tissue due to compromised blood flow.

In this scenario, when there's significant narrowing of the renal arteries, it can lead to secondary hypertension as the kidneys sense low perfusion pressure, activating the renin-angiotensin-aldosterone system (RAAS) and resulting in further increases in blood pressure. As the stenosis progresses, renal function deteriorates, leading to increased creatinine levels as the kidneys are unable to adequately filter waste products from the blood.

The identification of bilateral renal artery stenosis is crucial in this context since it directly links the recent elevation in blood pressure to the kidney's ability to maintain normal function, ultimately highlighting that both blood pressure increases and elevated creatinine levels occur due to insufficient blood supply to the kidneys.