Diuretics

Date Updated: 09/05/2025

Diuretics are medicines that help reduce fluid buildup in the body. They sometimes are called water pills. Most diuretics help the kidneys remove salt and water through the urine. This lowers the amount of fluid flowing through the veins and arteries. As a result, blood pressure goes down.

Examples of diuretics

Types of diuretics used to treat high blood pressure include:

Thiazide.
Loop.
Potassium sparing.

Some water pills combine more than one type of diuretic. Others combine a diuretic with a different medicine, such as a blood pressure medicine. Which type is best for you depends on your health and the condition being treated.

Examples of thiazide diuretics include:

Chlorothiazide (Diuril).
Chlorthalidone (Hemiclor, Thalitone).
Hydrochlorothiazide (Inzirqo, Microzide).
Indapamide.
Metolazone.

Examples of loop diuretics include:

Bumetanide (Bumex).
Ethacrynic acid (Edecrin).
Furosemide (Lasix, Furoscix).
Torsemide (Soaanz).

Examples of potassium-sparing diuretics include:

Amiloride (Midamor).
Eplerenone (Inspra).
Spironolactone (Aldactone, Carospir).
Triamterene (Dyrenium).

When diuretics are used

Diuretics are commonly used to treat high blood pressure. Thiazide diuretics usually are one of the first types tried. If diuretics aren't enough to lower your blood pressure, you may receive additional medicine.

Diuretics also are used to prevent, treat or improve symptoms for people who have:

Heart failure.
Liver failure.
Fluid buildup in the body.
Certain kidney conditions, such as kidney stones.

Side effects

Diuretics are generally safe. Side effects may include:

Urinating more often.
Too little sodium in the blood.
Too little potassium in the blood.

Other possible side effects of diuretics include:

Dizziness.
Headaches.
Not enough water in the body for it to work properly, also called dehydration.
Muscle cramps.
A type of arthritis called gout, which causes severe joint pain, usually in the big toe.
Not being able to get and keep an erection firm enough for sexual activity, also called erectile dysfunction or impotence.

Talk to your healthcare team if you have any questions about the medicines you take.