Diuretics are a type of medication often used to treat edema, a form of swelling that’s common with pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH). Edema occurs when fluid builds up and gets trapped in different parts of the body, and diuretics help your body flush out the excess.

Pulmonary hypertension itself can cause swelling, but people with PH also may experience edema from related health conditions, like congestive heart failure (CHF). Edema can also be a side effect of medications used to treat PH, such as calcium channel blockers and endothelin receptor antagonists.

People with edema may have symptoms such as:

• Swelling or puffiness under the skin of the legs and arms
• Skin that looks stretched or shiny
• Pitting (when skin stays dimpled after being pressed for a few seconds)
• Heavy-feeling legs
• Ascites (increased stomach size)

If you have edema, your doctor may prescribe a medicine called a diuretic — also known as a water pill — to help you get rid of excess water. Here are four things you should know about diuretics for edema.

1. Diuretics Reduce Swelling in Different Ways

Diuretics are a class of medications that help your body get rid of extra water and fluid. Your doctor will prescribe a diuretic based on your symptoms and the severity of your edema. There are several types of diuretics, and they work in different ways.

Most diuretics affect how your kidneys get rid of excess electrolytes (salts) like sodium, chloride, and potassium. In general, the excess fluid will follow where the salt goes and be excreted.

You might be on more than one type of diuretic at a time. One myPHteam member shared, “I have PH and CHF. I take Lasix, spironolactone, and metolazone for diuretics.”

Thiazide Diuretics

Thiazide diuretics prompt your kidneys to remove more sodium and water from your body through urine. They accomplish this by blocking salt reabsorption from your urine into your bloodstream. Examples of thiazide diuretics include:

• Hydrochlorothiazide (Microzide)
• Chlorthalidone (Thalitone)
• Metolazone (Zaroxolyn)

Thiazide diuretics are available as tablets you take by mouth.

Loop Diuretics

Loop diuretics work in a different part of the kidney — called the loop of Henle — to stop salt reabsorption from the urine into the blood. This results in more salt and water leaving through your urine. Loop diuretics include:

• Furosemide (Lasix)
• Torsemide (Demadex)
• Bumetanide (Bumex)

Loop diuretics can be taken by mouth or intravenously (injected into a vein). You might receive intravenous diuretics if you are in the hospital.

Potassium-Sparing Diuretics

Potassium-sparing diuretics help your kidneys let go of extra salt and water without losing too much potassium. These drugs block the hormone aldosterone, which normally tells the kidneys to hold on to salt and water. Diuretics such as the following help avoid the loss of potassium:

• Spironolactone (Aldactone)
• Triamterene (Dyrenium)
• Amiloride (Midamor)

Potassium-sparing diuretics are available as tablets you take by mouth.

Carbonic Anhydrase Inhibitors

Carbonic anhydrase inhibitors block the protein that turns carbonic acid into water and carbon dioxide, leading to increased sodium, potassium, and water in the urine.

Although carbonic anhydrase inhibitors don’t have a large diuretic effect, one drug in this class — acetazolamide (Diamox) — can treat PH by reducing lung inflammation.

2. You Should Plan for Frequent Bathroom Trips

Diuretics increase the amount of salt and fluid excreted in your urine, which makes you have to urinate (pee) more often.

A myPHteam member shared, “For me, my water pills make resting hard to do. It’s up down up down. I have an electric chair, but when the water pills are working, the chair is slow. Thank goodness for pullups.”

Talk to your doctor about the best time to take diuretics. For twice-daily dosing, morning or early afternoon might be best so you don’t wake up multiple times during the night to go to the bathroom.

Most people take diuretics without any serious problems occurring. However, like most medications, these drugs can lead to side effects, such as:

• Dizziness
• Dehydration
• Low blood pressure
• Headache
• Tiredness
• Nausea
• Constipation
• Muscle cramps

Rare but serious side effects while taking diuretics include:

• Hearing loss or tinnitus (ringing in your ears)
• Kidney damage
• Liver damage
• Gout
• Heart palpitations (irregular heartbeat)
• Unbalanced electrolytes

3. You May Need To Change What You Eat and Drink

Diuretics change the way your body handles certain electrolytes and water. Depending on your medical conditions, symptoms, and the type of diuretic you take, you may need to make dietary changes. Talk with your doctor about specific recommendations for you.

Fluid Intake

Heart failure is a common cause of pulmonary hypertension. If you also have heart failure, your doctor may ask you to keep your fluid intake under 6 to 9 cups per day. Some myPHteam members have shared how fluid restriction affects them. One member wrote, “I watch my salt intake and fluid intake, but I get so thirsty! Suggestions?”

Other myPHteam members shared tips for beating thirst while restricting fluid intake, such as this: “I’m struggling like you. The best thing I’ve found so far is frozen grapes. The combination of cold, sweet, and grape juice really helps with thirst. I’ve been drinking flavored seltzer water. It doesn’t have any sodium, artificial sweeteners, or flavorings and can be very thirst-quenching when ice cold.”

Another member warned, “Be careful with mineral water, because they consider sodium a mineral, and they are often high in sodium.”

Sodium Intake

Increased sodium (salt) in your diet can worsen edema symptoms by causing fluid retention. Your doctor may recommend that you eat less salt to limit that effect.

Members of myPHteam have shared their struggle with this. “I’m pretty good about watching my sodium intake,” says one member, “but sometimes, I have a day where I’ll just blow it. I know I’ll wake up the next day with puffy feet and legs and possibly shorter of breath.”

Potassium Intake

Most diuretics can decrease your potassium levels, which is called hypokalemia. Your doctor will check your potassium levels and may ask you to take a potassium supplement.

As their name suggests, potassium-sparing diuretics don’t usually cause hypokalemia. However, they may make your potassium levels too high — called hyperkalemia.

The symptoms of both high and low potassium are similar and include muscle weakness, muscle cramps, and heart palpitations.

4. It’s Important To Monitor Your Symptoms While on Diuretics

When you are taking diuretics, your doctor will perform regular blood tests to check your electrolyte levels and your kidney and liver function, as well as look for serious side effects.

It’s also important that you regularly monitor your symptoms at home so you know when you might need to seek medical attention. Your doctor may ask you to track your weight by stepping on your scale every day. If you gain more than 2 to 3 pounds in a single day or more than 5 pounds in a week, you should call your doctor right away.

“I found out just how important it is to watch my fluid intake and my weight daily,” commented one myPHteam member. “I didn’t do either, and between my cardiologist’s appointment and my pulmonologist’s appointment, which was one week, I gained 10 pounds and wasn’t feeling very good.”

Other warning signs that you should seek immediate care for include the following:

• Frequent cough
• Feeling short of breath while resting
• Increased swelling and discomfort in your legs and ankles
• New or worsening dizziness or confusion
• Lack of appetite
• Inability to lie flat or sleep well

Talk to your health care team to learn about the best edema treatment for you and which side effects you should watch for.

Talk With Others Who Understand

On myPHteam, the social network for people with pulmonary hypertension and their loved ones, over 50,000 members come together to ask questions, give advice, and share their stories with others who understand life with PH.

Have you taken a diuretic for edema caused by PH? Did you change your diet or make any other changes to manage side effects? Share your experience in the comments below, or start a conversation by posting on your Activities page.