Diuretics are a type of medication that increases the amount of water and salt that is expelled from the body in urine. They can treat a range of conditions, including high blood pressure and congestive heart failure.

Diuretics is the name for a group of medications that help rid the body of extra fluid or salt.

This article looks at the different conditions that diuretics can treat. It also lists the different types of diuretics, and outlines any potential side effects.

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One of the most common uses for diuretics is in the treatment of high blood pressure. They reduce the amount of fluid in the blood vessels, which helps lower a person’s blood pressure.

Doctors may also use diuretics to treat congestive heart failure. This is when the heart can no longer effectively pump blood around the body.

A person with congestive heart failure can end up with a buildup of fluids in their body. This can cause ankle swelling and fluid retention. Diuretics can help remove water from the body and reduce this buildup of fluid.

Other conditions that a person can use diuretics to treat include:

The three main types of diuretics are thiazides, loop diuretics, and potassium-sparing diuretics.


Thiazides promote natriuresis, which is the release of salt in urine, and diuresis, which increases the amount of urine a person produces. They also cause a person’s blood vessels to relax.

Medical professionals use thiazides to treat high blood pressure, edema (fluid buildup), and congestive heart failure.

A person takes these drugs orally and they usually begin to act within roughly 2 hours. Many thiazides, such as hydrochlorothiazide, work for approximately 12 hours.

A medical professional will usually administer thiazides early in the day so that the diuresis does not impact a person’s sleep.

Loop diuretics

Loop diuretics interfere with the transport of salt and water across cells in the kidneys. They cause the kidneys to pass out more fluid, which leads to increased urine production.

As more fluid passes out of the kidneys, less remains in the bloodstream. This means that any fluid that has built up in the tissues of the body can move back into the bloodstream to replace the fluids that the kidneys have passed out.

This can reduce the symptoms of edema and any breathlessness that fluid congestion may have caused.

Medical professionals use loop diuretics to manage and treat fluid buildup and conditions related to fluid buildup. These conditions include heart failure, nephrotic syndrome or cirrhosis, high blood pressure, and edema.

Potassium-sparing diuretics

Potassium-sparing diuretics, such as amiloride, cause a person’s fluid levels to reduce without causing them to lose potassium. Other types of diuretics can cause a person’s potassium levels to drop.

If a person’s potassium levels drop too far it may result in health problems such as arrhythmia.

Potassium-sparing diuretics are not as effective as other diuretics at reducing blood pressure. However, they do allow retention of potassium.

Therefore a medical professional may prescribe potassium-sparing diuretics to a person alongside thiazides or loop diuretics in order to keep a person’s potassium levels from dropping too much.

When a person takes diuretics, they may experience one of a number of side effects. These include:

  • weakness
  • dizziness
  • an electrolyte imbalance
  • low sodium levels
  • low potassium levels

In some rare cases a person may experience more serious side effects, including allergic reactions, kidney failure, and an irregular heartbeat.

If a person is experiencing side effects when taking diuretics they should speak to a doctor. The doctor may be able to prescribe a different medication.

A person should never stop taking their diuretics before consulting a doctor.

Diuretics are generally safe for most people. However, some people with specific conditions may be at risk of more serious issues if they take diuretics.

Certain conditions

Diuretics may worsen the symptoms of pancreatitis, which can put a person at an increased risk of acute pancreatitis.

A person should also inform their doctor if they have diabetes before they take diuretics. This is because some diuretics may cause abnormal glucose tolerance, which could worsen the symptoms of diabetes.

However, it is worth noting that some diuretics, particularly thiazides, do play a key role in the management of type 2 diabetes and hypertension.

Diuretics can raise a person’s risk of developing gout. Therefore a person who has gout should inform their doctor before taking any diuretics that the doctor may prescribe.

Medical professionals also recommend that people who are pregnant or breastfeeding avoid taking diuretics.

Other conditions that diuretics may make worse include:

Drug interactions

Some drugs may interact with diuretics. A person should therefore inform their doctor about any medication they are taking before they begin to take diuretics.

Some common medications that may interact with diuretics include:

  • laxatives
  • oral antidiabetic agents
  • antihypertensive agents
  • potassium
  • magnesium
  • acid salts

Herbal/plant diuretics

There are a number of natural diuretics that a person can eat or drink. However, it is worth noting that these diuretics should not replace prescription medication that a person may require to treat certain conditions.

Some natural diuretics include:

  • nigella sativa, sometimes called black cumin, black seed, or black caraway
  • hibiscus
  • ginger
  • parsley
  • green and black tea

Diuretics can increase urine production in the body. They also increase the amount of salt that the body expels.

Thiazides, loop diuretics, and potassium-sparing diuretics are the three main types of diuretics.

Medical professionals use diuretics to treat a range of conditions, including high blood pressure, edema, and congestive heart failure.

Some potential side effects of taking diuretics include weakness, dizziness, an electrolyte imbalance, and low levels of sodium and potassium.

Diuretics may also make some conditions worse. People with certain conditions, including pancreatitis, diabetes, and gout, should inform their doctor of their condition before taking diuretics.