Diuretic and How It Works with Blood Pressure

Yes, diuretics can cause constipation if you don't drink enough fluids. Diuretics can help you manage your high blood pressure and other conditions, but you need to take them the right way.

Medications such as diuretics can be key for people with high blood pressure. By causing you to urinate more often, the drugs can help remove excess water and salt from your body. In turn, diuretics can help lower blood pressure and reduce the risk of complications such as heart attacks or strokes.

Diuretics ― also known as water pills ― are medicines that help you move extra fluid and salt out of your body. They make you pee more frequently, which is why you should take them in the morning if you can. You may need to take diuretics once or twice a day at the same time each day.

Types of diuretics include:

Thiazide diuretics, such as hydrochlorothiazide (Microzide® or Oretic®) or chlorthalidone (Hygroton® or Thalitone®). What they do: They make your kidneys pull salt and extra water into your pee. Selected side effects:

Headache.
Loss of appetite.
Hair loss.

Loop diuretics, such as furosemide or bumetanide What they do: They affect part of your kidneys (the loop of Henle) to get salt and excess water out of your body. Selected side effects:

Dizziness.
Diarrhea.
Upset stomach.

Potassium-sparing diuretics, such as triamterene or amiloride What they do: They help your kidneys clear salt and water out of your body, but don’t let you lose too much potassium in the process. Selected side effects:

Gas.
Nausea.
Headache.

A mixture of two types in one pill, like triamterene and hydrochlorothiazide (Dyazide® or Maxzide®) What they do: They make your kidneys move salt and extra water out while keeping you from losing too much potassium. Selected side effects:

Headache.
Peeing often.

People usually take diuretics by swallowing diuretic pills, but your provider can give some diuretics through an IV in your arm during a hospital stay. Most people can take diuretics without getting serious problems from them.

How do diuretics work?

Diuretics make your kidneys take away your body’s extra salt and water by putting them into your urine (pee).

Who needs diuretics?

People who have high blood pressure or have too much fluid collecting in their bodies need diuretics.

Why do providers prescribe diuretics?

Diuretics bring down blood pressure because they help your blood vessels get wider. Also, there’s a smaller amount of fluid in your blood to pump. Diuretics also help your body clear out extra fluids.

What do diuretics treat?

Diuretic medications can help with:

High blood pressure.
Heart failure.
Cardiomyopathy.
Pulmonary edema.
Ascites.
Renal failure.
Nephrotic syndrome.
Diabetes insipidus.
High intraocular pressure.
High intracranial pressure.

How common are diuretics?

Diuretics are very common. A list of America’s most frequently prescribed drugs includes two diuretic drugs in the top 15.

What are the advantages of diuretics?

Diuretics give many people ― even older adults ― good results, especially for treating high blood pressure. Also, people generally don’t have bad side effects with diuretics.

What are the risks or complications of diuretics?

Usual side effects of diuretics include:

Peeing more than usual.
Dizziness.
Tiredness.
Headache.
Gout.
Difficulty getting an erection.
Low potassium (unless you’re taking a potassium-sparing type of diuretic).
Muscle cramps.
Heart palpitations.
Higher blood sugar in people with diabetes.
Dehydration.
Unbalanced electrolytes.

Your provider will want to make sure your kidneys are working right and your potassium level is normal when you’re taking diuretic pills. If you’re pregnant, breastfeeding, an older adult or have problems with your kidneys or liver, discuss the risks of diuretics with your provider.