Renin is an enzyme that helps control your blood pressure and maintain healthy levels of sodium and potassium in your body. Made by special cells in your kidneys, renin is released into your bloodstream when your blood pressure drops too low.
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Blood pressure regulation is the main function of renin. It works together with angiotensin and aldosterone to manage the levels of sodium and potassium in your body.
Here’s how the process works:
Renin is released into your bloodstream when your blood pressure drops too low or when there’s not enough sodium in your body. Specifically, renin secretion happens when:
Not exactly. On its own, renin doesn’t affect your blood pressure. Instead, it works together with angiotensin and aldosterone to accomplish this. Angiotensin narrows your blood vessels and aldosterone causes your kidneys to retain water and salt. This increases the amount of fluid in your body and raises your blood pressure.
Renin is produced in your kidneys. When your systolic blood pressure falls or your kidneys sense that you are volume depleted, your kidneys release renin into your bloodstream.
Renin contains 340 amino acid residues. (When two or more amino acids combine and form a peptide, water is removed. What’s left is called amino acid residue.)
Increased renin levels are linked to several conditions, including:
Yes. A renin activity test along with aldosterone level can tell your healthcare provider how much aldosterone your adrenal glands are making. Your provider may recommend this test if you’ve been diagnosed with high blood pressure, especially if standard high blood pressure medications aren’t working.
If standard medications don’t successfully manage high blood pressure, then you could have a condition called primary aldosteronism (PA) — sometimes called Conn’s syndrome. People with too much aldosterone can develop PA, and they often have high blood pressure. A renin activity test can determine if your high blood pressure is caused by PA.
Renin is most often measured as plasma renin activity (PRA). It measures how well renin generates angiotensin I (the precursor of angiotensin II). It can also be measured as direct renin.
High renin levels could mean that you have:
Low renin levels could be from:
If your renin levels are abnormally high or low, your healthcare provider will design a treatment plan based on the underlying cause. For example, if you have high renin levels and high blood pressure, your provider may prescribe beta-blockers, clonidine or other medications to lower your blood pressure.
A note from Cleveland Clinic
Renin is an essential element of the renin-angiotensin-aldosterone system, and it plays a vital role in regulating your blood pressure. There are many reasons for abnormal renin levels. Your healthcare provider can help identify the root cause and recommend the appropriate treatment.
Last reviewed by a Cleveland Clinic medical professional on 02/17/2022.
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