What Is Fluid Overload?

Written by Clarissa Brincat
Medically Reviewed by Poonam Sachdev on June 02, 2025
7 min read

Normally, your body is made of about 50%-60% fluid, including water, blood, and lymphatic fluid. When your fluid levels are out of balance (too high or too low), serious health problems can happen.

Fluid overload is also called hypervolemia. It’s when you have too much fluid in your body. It can be caused by several different conditions, including heart failure, kidney failure, cirrhosis, or pregnancy.

Hypervolemia vs. hypovolemia

Hypervolemia and hypovolemia are two conditions that affect the body’s fluid levels. The prefix “hyper-” means ctoo much,” while “hypo-” means “too little,” and ”vol” refers to volume. Hypervolemia is when there is an excess of fluid in the body, whereas hypovolemia is when fluid levels are too low.

You may have symptoms from the underlying condition that’s causing your fluid overload. As many serious conditions can cause fluid overload, it needs to be treated. Call your doctor if you have any of these symptoms:‌

Swelling. You may have swelling in your feet, legs, hands, or face. Swelling caused by too much fluid in your body is called edema. If you press on swollen skin with your thumb and it leaves a dent, it’s called pitting edema.

High blood pressure. The extra fluid in your body makes your heart work harder. This raises your blood pressure.

Shortness of breath. It can be difficult for you to breathe if the extra fluid gets into your lungs. You might also make a sound called a crackle when you breathe. You need to see your doctor immediately if you are having trouble breathing.‌

Discomfort. You might have a headache, stomach bloating, or abdominal cramps, which can make you feel uncomfortable.

Weight gain. This is usually the first sign of fluid overload. Most people gain 8-15 pounds before they notice swelling in their legs or abdomen.‌

Chest pain. This can be a sign of pulmonary edema, which means there’s fluid in your lungs. You need to see your doctor immediately if you have chest pain.

Fluid overload affects people with medical conditions or lifestyle factors that affect how the body controls fluids or responds to cues to take in or get rid of fluids. Those at higher risk include:

  • People who consume too much salt (sodium): A high-sodium diet can cause your body to hold onto water, leading to fluid overload.
  • People who receive IV fluids: Receiving too much fluid in a short period can result in fluid overload.
  • People with heart failure: When your heart can’t pump blood effectively, blood and fluid can collect in your lungs and legs.
  • People with kidney conditions: The kidneys play an important role in maintaining fluid balance. When they aren’t functioning properly, fluid can build up.
  • People with liver conditions: Liver diseases, such as cirrhosis and hepatitis, can lead to fluid buildup in the abdomen (known as ascites), and in your hands, feet, legs, and/or face (edema).
  • People with diabetes: Diabetes can damage the kidneys and lead to fluid retention.
  • People taking certain medicines: Some drugs, especially blood pressure and pain management medications, can cause fluid overload as a side effect.
  • People experiencing hormonal changes: Changes in hormone levels before menstruation cause the body to hold in excess water.
  • Pregnant people: When the growing uterus puts pressure on blood vessels in the lower body, it limits blood from returning to the heart. Combined with hormonal changes and increased fluid retention during pregnancy, this can lead to fluid overload.

Fluid overload happens when your kidneys retain sodium. Your kidneys manage the salt and fluid balance in your body. When something causes your kidneys to retain sodium, it raises sodium levels in the rest of your body. This causes your body to make too much fluid. Several different conditions can cause this, such as: 

Heart failure. When your heart muscle is weak, damaged, or too stiff, it might cause the heart to not pump blood as well as it should. Your kidneys may not get enough blood to function properly. Your body retains fluid and salt to try to correct the balance.

Cirrhosis. Liver disease can cause a buildup of scar tissue on your liver. Your liver can't function as well with scar tissue. This can cause fluid to build up in your abdomen.

Kidney failure. Your kidneys clean your blood and get rid of toxins in your body. They also balance the amount of fluid and salt in your body. Fluid can build up in your body when your kidneys are not working the way they should.

Nephrotic syndrome. This is a kidney disorder usually caused by damage to small blood vessels in your kidneys. These blood vessels filter waste and extra water from your blood. When they are damaged, your body can’t get rid of excess fluid.‌

Other conditions. Fluid overload can also be caused by other conditions, such as pregnancy or premenstrual edema.

Your doctor will do a physical exam and talk to you about your symptoms and medical history. Your doctor may be able to diagnose you with fluid overload based on edema and weight gain. You may also need further lab or imaging tests to find out the underlying cause.

Your doctor will treat the underlying cause of your fluid overload. Treatment options may include:

  • Diuretics — medicines that help you get rid of extra fluid
  • Dialysis — a treatment that filters your blood through a machine
  • Paracentesis — a procedure that uses a small tube to drain fluid from your abdomen
  • Limiting your salt intake
  • Checking your weight daily

Some causes of fluid overload may respond to certain lifestyle changes. To manage fluid overload, try the following:

  • Quit smoking.
  • Take your medicines as directed.
  • Maintain a healthy weight.
  • Keep track of how much fluid you drink.
  • Do not drink too much alcohol.
  • Eat a healthy diet.
  • Avoid too much caffeine.
  • Get enough exercise.
  • Manage your stress.
  • Get enough sleep.
  • Keep track of your blood pressure.
  • Control your blood sugar if you have diabetes.
  • Stay up to date with your flu and pneumonia vaccines.

If left untreated, fluid overload can cause serious complications, such as:

  • Pulmonary edema
  • Heart failure
  • Delayed wound healing
  • Tissue breakdown
  • Problems with your bowel function

Fluid overload and heart failure

Fluid overload is a major concern for patients with chronic heart failure.

When the heart is weakened and can’t pump blood efficiently, it sends a distress signal to your kidneys. In response, the kidneys start to retain sodium and water, trying to boost the volume of blood circulating in your body. This is your body’s way of making up for poor circulation, but it causes fluid buildup in the blood vessels, as well as between cells and tissues.

Your body can also shift fluid from hidden storage areas (such as abdominal veins) into the lungs. This shift — called fluid redistribution — can cause sudden shortness of breath and may require hospitalization.

You can prevent fluid overload by maintaining a proper balance between sodium intake and fluid output, says Shweta Bansal, MD, a nephrologist at the University of Texas, San Antonio. “It is very important to cut down salt intake in your diet — particularly from processed foods, which are very high in sodium.”

The American Heart Association (AHA) recommends a maximum of 2,300 milligrams (mg) of sodium per day for most adults, with an ideal limit of 1,500 mg per day. Bansal notes that this can be challenging, but “any reduction from your current intake is welcome.”

Increasing fluid output is also important. This can be done by taking diuretic pills, which help the body get rid of excess fluid. For individuals on dialysis, it can be done through ultrafiltration — a process that removes excess fluid directly from the blood, Bansal explains.

Fluid overload (hypervolemia) happens when there’s too much fluid in the body, often due to conditions such as heart failure, kidney disease, or liver problems. Common symptoms include swelling, high blood pressure, shortness of breath, discomfort, weight gain, and chest pain. If untreated, it can lead to serious complications like pulmonary edema or heart failure. Treatment focuses on treating the underlying cause and may include diuretics, dialysis, and lifestyle changes. To help prevent fluid overload, reduce your sodium intake and follow your doctor’s recommendations.

What is a fluid overload in the lungs?

Fluid overload in the lungs, also known as pulmonary edema, is a condition in which excess fluid builds up in the lung’s air sacs (alveoli). This makes it hard for oxygen to move into the bloodstream, leading to shortness of breath.

What is the best indicator of fluid overload?

There isn’t a single best indicator yet, says Bansal. Instead, doctors rely on a combination of information, such as physical exams, blood pressure trends (how much it changes over time), chest X-rays (which can show fluid buildup in the lungs), point-of-care ultrasound (a quick bedside scan to look for fluid overload in the heart and lungs), blood volume analysis (measuring how much blood is in the body), bioimpedance analysis (a test that estimates body fluid levels by sending small electrical currents through the body), and monitoring of plasma volume (the liquid part of your blood), she says.

Will dialysis remove fluid from the lungs?

Yes, by removing excess fluid from the blood, dialysis can help reduce the fluid content in the lungs.