Diuretics can help various medical conditions because of too much fluid.
They lower blood pressure by reducing the fluid in your blood that your heart has to pump.
This article discusses what diuretics treat and how they work.
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It also covers the types of diuretics, side effects, risks, and complications.
What Do Diuretics Treat?
Healthcare providers may prescribe diuretics to decrease fluid levels when treating various conditions.
These include:
In some cases, diuretics may need to be taken long-term.
In others, they can be discontinued once symptoms improve.
Diuretics are sometimes taken alongside other medications to treat conditions like high blood pressure and heart failure.
Types of Diuretics
There are several types of diuretics your healthcare provider may prescribe.
Each medication has a different way that it works to remove fluid or salt from the body.
Herbal supplements arent regulated like medications and may cause drug interactions.
Always check with a healthcare provider before taking a supplement.
The medicine works by limiting an enzyme called carbonic anhydrase.
This is an enzyme in the kidney that puts minerals, sodium, and water back in your blood.
The medication limits this enzyme, so it increases the amount of water that leaves your body through urine.
Loop Diuretics
Loop diuretics affect a part of your kidneys called the loop of Henle.
They remove salt and excess water from your body.
Loop diuretics may also cause you to lose too much potassium.
If the potassium loss is severe enough,hypokalemia(low potassium levels) can result.
In severe cases, hypokalemia can lead to abnormal heart rhythms and even cause it to stop.
This causes more water to leave the body as urine.
Like loop diuretics, thiazides can also cause the levels of potassium in your body to drop.
Your doctor will monitor your potassium levels while youre taking the medicine.
In some cases, thiazides may be combined with loop diuretics to increase their effects.
Thiazides are also used to treat calcium-containing kidney stones anddiabetes insipidus.
Potassium-Sparing Diuretics
As their names suggest, potassium-sparing diuretics work by increasing urine volume without decreasing potassium.
Potassium-sparing diuretics include spironolactone and amiloride.
Spironolactone prevents the action ofaldosterone, a steroid hormone produced by the adrenal gland.
It causes the kidneys to get rid of extra water and sodium while reducing the loss of potassium.
Spironolactone is often used to counteract potassium loss sparked by thiazide and loop diuretics.
It may also be used to treathyperaldosteronism.
Amiloride blocks the reabsorption of water into your body.
Like spironolactone, amiloride is often used to counteract potassium loss resulting from other diuretics.
Osmotic Diuretics
Osmotic diuretics draw in water through osmosis.
Osmosis is the passing of water from a less concentrated solution to a more concentrated solution.
Osmotic diuretics prevent water from being reabsorbed and allow it to exit the body.
This can treat glaucoma as well as increased intracranial pressure.
Osmotic diuretics are also used to prevent acute kidney (renal) failure afterchemotherapyorrhabdomyolysis(muscle breakdown).
This increases the level of sodium in the blood.
What Are Natural Diuretics?
Some herbs and supplements may act as natural diuretics.
These include dandelion, ginger, juniper, hawthorn, and parsley.
Always check with your healthcare provider before taking a supplement to check that its safe for you.
In contrast, potassium-sparing diuretics may cause potassium levels to become too high.
This can potentially lead to dangerous heart-rhythm conditions or cardiac arrest.
Diuretics could also contribute to dehydration due to fluid loss if you arent drinking enough water.
How Diuretics Work
Diuretics help your kidneys remove salt from your body.
This helps your body produce more urine.
Each of your kidneys has about a million nephrons.
Diuretics limit the amount of sodium that can be absorbed by nephrons.
Some diuretics work by inhibiting the reabsorption of water.
They do this by blocking receptors for vasopressin, the hormone responsible for maintaining water levels in your body.
It usually takes about one to two hours for diuretics to start working.
Summary
Diuretics treat medical conditions due to too much fluid.
They help remove extra salt and fluid from the body by increasing urine.
Kehrenberg MCA, Bachmann HS.Diuretics: a contemporary pharmacological classification?.Naunyn Schmiedebergs Arch Pharmacol.
2022;395(6):619-627. doi:10.1007/s00210-022-02228-0
HCA Virginia Physicians.The truth about water pills and weight loss.
American Academy of Ophthalmology.Acetazolamide: considerations for systemic administration.
Simes BC, MacGregor GG.Sodium-glucose cotransporter-2 (SGLT2) inhibitors: a clinician’s guide.Diabetes Metab Syndr Obes.
2019;12:21252136. doi:10.2147/DMSO.S212003
Oh SW, Han SY.Loop diuretics in clinical practice.Electrolyte Blood Press.
2015;13(1):17-21. doi:10.5049/EBP.2015.13.1.17
UpToDate.Diuretics and calcium balance.
2022;18(2):e151021197270.
doi:10.2174/1573403X17666211015145132
National Library of Medicine: MedlinePlus.Amiloride.
Abdallah HM.New trends in pharmacological treatment of acute kidney injury.Asian Pac J Trop Biomed.
2017;17(1).
doi:10.1186/s12872-017-0598-y
Texas Heart Institute.Diuretics.
Harvard Health Publishing.Tips for taking diuretic medications.
2019;11(3):669. doi:10.3390/nu11030669
Brater DC, Ellison DH.Mechanism of action of diuretics.
In: Sterns RH, Emmett M, eds.UpToDate.
