How Do Diuretics Affect the Kidneys?
Also known as water pills, diuretics are medications recommended to treat a number of conditions where your body’s ability to regulate water is affected, such as kidney disease. Different types of diuretics exist, but one type -- known as a loop diuretic -- affects how the kidneys regulate water in the body, encouraging the release of built-up water in the body.
How the Kidneys Work
Your kidneys are the filters of your body and maintain the delicate fluid balance. Because your body is about three-quarters water, having the right fluid amounts is important. Too much fluid increases your blood pressure and not enough can dry out blood and skin cells, causing dehydration. The kidneys regulate water through a system known as the renin-angiotensin-aldosterone system. When the kidneys sense too much water in the body, they signal the release of these hormones, which encourage you to urinate to get rid of excess water. When you don’t have enough water, the kidneys retain these hormones, making you hold on to more water in your body.
- Your kidneys are the filters of your body and maintain the delicate fluid balance.
- When the kidneys sense too much water in the body, they signal the release of these hormones, which encourage you to urinate to get rid of excess water.
Sodium and Your Kidneys
Water Pills That Don't Adversely Affect the Kidneys
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Your kidneys use sodium as a means to retain water in the body. Sodium and water are naturally attracted to each other. Because sodium is the major ion outside your cells, extra salt outside your cells causes your body to retain water -- this is why you tend to become bloated after a salty meal. If your kidneys sense you do not have enough water in your body, they will take in more sodium through the foods and drinks you consume, which then increases your fluid levels in the body. Loop diuretics directly affect this process in the kidneys by signaling the body not to absorb sodium.
- Your kidneys use sodium as a means to retain water in the body.
- If your kidneys sense you do not have enough water in your body, they will take in more sodium through the foods and drinks you consume, which then increases your fluid levels in the body.
Specific Process
When you take a diuretic, the medication moves to the kidneys. Inside the kidneys are small loops known as the loops of Henle that regulate sodium intake. The medication signals the calcium/potassium pump in the kidneys to stop taking in sodium. However, this flushes out minerals like calcium, potassium and magnesium, which is why potassium loss can be a side effect of taking a loop diuretic. The sodium that is released attracts water in the body, causing your body to release it.
- When you take a diuretic, the medication moves to the kidneys.
- The medication signals the calcium/potassium pump in the kidneys to stop taking in sodium.
When They’re Prescribed
Why Don't Water Pills Work Anymore?
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Loop diuretics for the kidneys are prescribed for a number of medical conditions. If you are experiencing kidney failure, diuretics can help make up for lost kidney function. They also are prescribed when patients are experiencing edema -- a condition that causes water retention. If you have excess potassium in your blood, a physician may prescribe a diuretic. Remember that diuretics can have toxic effects when they are taken without a physician’s advice. Always talk to your doctor before taking a diuretic.
- Loop diuretics for the kidneys are prescribed for a number of medical conditions.
- If you have excess potassium in your blood, a physician may prescribe a diuretic.
Related Articles
References
- Texas Heart Institute: Diuretics
- ABC News; How Do Diuretics, or 'Water Pills,' Work?; Dr. Deepak Bhatt; November 2008
- National Kidney and Urologic Diseases Information Clearinghouse; High Blood Pressure and Kidney Disease; July 2008
- The George Washington University: Diuretics/Diet Pills
- Duarte JD, Cooper-DeHoff RM. Mechanisms for blood pressure lowering and metabolic effects of thiazide and thiazide-like diuretics. Expert Rev Cardiovasc Ther. 2010;8(6):793–802. doi:10.1586/erc.10.27
- U.S. National Library of Medicine, StatPearls. Thiazide Diuretics. Updated February 4, 2019.
- U.S. National Library of Medicine, StatPearls. Loop Diuretics. Updated October 15, 2019.
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- Harvard Health Publishing, Harvard Medical School. Tips for Taking Diuretic Medications. Updated September 25, 2019.
- American Heart Association. Changes You Can Make to Manage High Blood Pressure. Reviewed November 30, 2017.
Writer Bio
Rachel Nall began writing in 2003. She is a former managing editor for custom health publications, including physician journals. She has written for The Associated Press and "Jezebel," "Charleston," "Chatter" and "Reach" magazines. Nall is currently pursuing her Bachelor of Science in Nursing at the University of Tennessee.