Fluid or water retention occurs when the body is unable to maintain fluid levels. Kidney or cardiovascular disease, for instance, may cause the body to retain fluid. The main symptoms are swelling and discomfort.

The circulatory system, the kidneys, the lymphatic system, hormonal factors, and other bodily systems help maintain healthy fluid levels. If a problem arises with one or more of these systems, however, fluid retention — otherwise known as edema — can occur.

Edema can affect any area of the body. It happens for a variety of reasons.

This article will look at some causes and symptoms of water retention, as well as how to treat it.

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The human body uses a complex system to regulate its water levels. Hormonal factors, the cardiovascular system, the urinary system, the liver, and the kidneys all play a role. If there is a problem with any of these parts, the body may be unable to expel fluid as it should.

Capillary damage

Capillaries are tiny blood vessels that play a key role in managing fluid balance in the body by delivering fluid to surrounding tissues. This fluid, called interstitial fluid, supplies nutrients and oxygen to cells. After delivering the nutrients, the fluid returns to the capillaries.

If the capillaries sustain damage, edema can occur. Possible problems include changes in pressure inside the capillaries and the capillary walls becoming too leaky.

If these problems occur, too much liquid can leave the capillaries and enter the spaces between cells. If the capillaries cannot reabsorb the fluid, it will stay in the tissues, causing swelling and water retention.

Some people experience this type of edema because they have a rare condition known as systemic leaky capillary syndrome.

Congestive heart failure

The pumping action of the heart helps maintain normal pressure within the blood vessels. If a person’s heart stops working effectively, their blood pressure will change. Fluid retention can arise from this.

There may be swelling in the legs, feet, and ankles, as well as fluid in the lungs, which can result in long-term cough or breathing difficulties.

Eventually, congestive heart failure can lead to breathing problems and stress on the heart. It can therefore be life threatening.

The lymphatic system

The lymphatic system carries lymph through the body. Lymph is a fluid that contains white blood cells. It helps the immune system defend the body against infection. As the lymphatic system delivers and reabsorbs lymphatic fluid, it also helps the body maintain fluid balance.

If a problem prevents the lymphatic system from working properly, fluid can build up around the tissues. This is called lymphedema and can cause swelling in various parts of the body, including the abdomen, ankles, legs, and feet.

Cancer, infections, and blockages can all cause problems with this system.

The kidneys

The kidneys filter the blood and help maintain fluid levels in the body.

Waste, fluids, and other substances pass into tiny tubules in the kidneys, which act as a filter. The bloodstream reabsorbs anything the body can reuse and removes the waste in the urine.

If the kidneys do not work properly, they cannot remove waste material, including fluids and sodium. The fluid will, therefore, stay in the body.

People with chronic kidney disease, for example, may notice swelling in the lower limbs, hands, or face.

Pregnancy

During pregnancy, the body holds more water than usual, leading to swelling in the lower limbs — especially during hot weather or after standing for a long time.

If the swelling suddenly becomes more severe, however, it may be a sign of pre-eclampsia. This is a type of high blood pressure that can harm both the mother and the fetus.

Anyone who experiences headaches, vomiting, pain under the ribs, vision problems, along with increased swelling during pregnancy, should seek immediate medical attention.

Physical inactivity

People with mobility problems or living a sedentary lifestyle can develop edema in the lower legs. Underuse can cause the calf muscle pump to lose strength.

It may help to:

  • keep the feet raised
  • wear compression stockings
  • practice exercises, such as raising and lowering the feet or rotating the ankles

Obesity

People with obesity may experience swelling due to the extra weight they carry. Obesity also increases the risk of high blood pressure, kidney disease, and heart disease, all of which can result in edema.

Obesity also increases the risk of metabolic syndrome, which includes type 2 diabetes, high blood pressure, and other health issues.

Malnutrition

Albumin is a protein that helps the human body manage fluids. When a person has a severe protein deficiency, it may be harder for the body to move interstitial fluid back into the capillaries.

When a person is severely malnourished, they may develop kwashiorkor. Symptoms include a loss of muscle mass and an enlarged abdomen. This is due to fluid retention in the bodily tissues.

Allergies

Allergic angioedema is when a localized body part becomes swollen due to contact with an allergen. For example, people with a specific food allergy may experience swelling in and around the mouth after eating an allergen. This occurs due to a build-up of fluid in the deep layers of skin during an inflammatory allergen response.

People may also experience hereditary angioedema, experiencing swelling without direct allergen contact.

Medications

Some medications can also lead to water retention.

These include:

Anyone concerned about swelling while using medication should speak to their doctor. They may be able to change the dosage or suggest an alternative.

Hormonal conditions

A hormonal imbalance can lead to fluid retention in the following ways:

  • Menstruation: Changes in hormonal balance can result in fluid buildup before menstruation. A person may experience bloating and breast tenderness as a result.
  • Thyroid problems: The thyroid gland releases hormones that play a role in managing fluid levels. People with conditions that affect the thyroid gland may, therefore, experience water retention.
  • Cushing’s syndrome: This condition causes the adrenal gland to produce too much steroid hormone, leading to leg swelling.

The symptoms of fluid retention will depend on the area it affects. Common areas include the lower legs, the hands, the abdomen, and the chest.

In the limbs, feet, and hands, symptoms include:

  • swelling
  • changes in skin color
  • shiny or puffy skin
  • areas of skin that remain indented when pushed in with a finger, known as pitting edema
  • aches and tenderness in the limbs
  • stiffness in the joints
  • weight gain

Fluid retention can also affect the following areas:

The brain

Fluid retention in the brain is known as cerebral edema. This can cause symptoms including vomiting, blurred vision, headache, and difficulty with balance. This can be life threatening.

The lungs

Excess fluid in the lungs, or pulmonary edema, can indicate a serious problem with the heart or respiratory system. Symptoms include difficulty breathing, a cough, chest pain, and weakness, which can affect the lungs’ ability to supply oxygen to the body.

Many cases of edema will resolve without treatment. If there is an underlying condition, a doctor will focus on treating that.

Diuretics are one treatment option. They can help the kidneys remove fluid from the body. These are usually short-term options, however, as they can cause side effects such as dehydration and kidney damage.

Some causes of fluid retention need medical treatment, but home remedies may help relieve the symptoms. The sections below discuss some of these in more detail.

Herbal remedies

Some herbs are natural diuretics. Some people believe that the extract of dandelion (Taraxacum officinale) may help reduce the amount of water the body retains in a day.

However, the National Center for Complementary and Integrative Health notes that as a food, dandelion is “generally considered safe,” although there is no scientific evidence to show that it has any medicinal use or that it is safe as a treatment. Some people may also have an allergy to it.

A person should speak to a doctor before using this or other herbal remedy. Diuretics may not be safe for people with low blood pressure or taking other medications that affect fluid and electrolyte balance.

Elevation

If a person has edema in their lower limbs, it may help to:

  • sit with the legs raised above the heart several times each day
  • sleep with the affected limb on a pillow to raise it above the level of the heart
  • have a massage, in which someone strokes the affected area firmly but gently toward the heart

Clothing

People with edema may wish to wear loose clothing, as it will be more comfortable and allow fluid to circulate.

Use support stockings to increase circulation in the lower limbs.

Diet

One method of managing water retention is through dietary changes. For example, studies show that sodium consumption can increase water retention. Limiting salt content in the diet can help to keep sodium levels in a healthy range, decreasing water retention.

Other research has found magnesium supplements can reduce many premenstrual symptoms, including water retention and bloating.

To reduce or prevent water retention, try:

  • managing weight
  • getting regular exercise
  • wearing support stockings, if edema affects the lower limbs
  • avoiding sitting or standing still for too long
  • taking breaks to walk around during long journeys
  • avoiding extreme temperatures, such as hot baths, showers, and saunas

Although it is not always possible to prevent fluid retention, following a healthy diet and getting plenty of exercise can help reduce the risk.

Water retention, also known as edema and fluid retention, is a buildup of fluid in the body. This can occur in cavities, tissues, and the circulatory system.

The primary symptom of water retention is swelling. Most cases of water retention resolve without medical intervention, and maintaining a healthy diet and lifestyle balance can often prevent the condition.