Water, or fluid, retention occurs when there is a problem with one or more of the body's mechanisms for maintaining fluid levels. The main symptoms are swelling and discomfort.
The circulatory system, the kidneys, the lymphatic system, hormonal factors, and other bodily systems all 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.
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:
- 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 limbsfu
- stiffness in the joints
- weight gain
Fluid retention can also affect the following areas:
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, as it 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 a short-term option, however, as they can cause side effects such as dehydration, increased water retention, and kidney damage.
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 one of these parts, the body may not be able to expel fluid as it should.
The sections below discuss the potential causes of fluid retention in more detail.
Capillaries are tiny blood vessels with a key role in managing fluid balance in the body. Some medications, such as those for high blood pressure, can cause damage to the capillaries.
Capillaries deliver 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 become damaged, edema can occur. Possible problems include changes in pressure inside the capillaries and the capillary walls becoming too leaky.
If these problems do 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 a 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 start to build up around the tissues. This 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.
What causes swelling in the ankles? Learn more here.
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 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.
During pregnancy, the body holds more water than usual, and this can lead to swelling in the lower limbs — especially during hot weather or after standing for a long time.
Hormonal changes and carrying extra weight in the abdomen can also contribute.
This is not usually dangerous, and it mostly resolves after delivery.
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, or vision problems along with increased swelling during pregnancy should seek immediate medical attention.
People with mobility problems or 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
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.
Albumin is a protein that helps the human body manage fluids. When a person has a severe protein deficiency, it may be harder for their 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.
What is malnutrition, and who is at risk? Learn more here.
Infections and allergies
The immune system's role is to defend the body from disease and infection. When the immune system detects an unwanted invader, such as bacteria or an allergen, it will mount an attack. Inflammation is part of this process.
When inflammation occurs, the body releases histamine. Histamine causes the gaps between the cells of the capillary walls to widen. It does this to allow infection-fighting white blood cells to reach the site of inflammation.
However, it can also allow fluid to leak from the capillaries into the surrounding tissues. The swelling that results from this is usually short-term.
People with long-term inflammation may experience water retention.
Some medications can also lead to water retention.
- calcium channel blockers
- nonsteroidal anti-inflammatory drugs
- some hormonal therapies, including some birth control pills
- prednisone, which is a corticosteroid
- some diabetes medications
Anyone who has concerns about swelling while using a medication should speak to their doctor. They may be able to change the dosage or suggest an alternative.
Edema can develop when a person uses birth control pills. What other adverse effects can arise? Find out here.
A hormonal imbalance can lead to fluid retention in the following ways:
Menstruation: Changes in hormonal balance can result in a buildup of fluid 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 a condition that affects 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 swelling in the legs.
Dependent edema occurs when fluid pools in the lower part of the body. Learn more here.
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.
Some herbs are natural diuretics. The extract of dandelion (Taraxacum officinale), for example, may help reduce the amount of water the body retains in a day.
The National Center for Complementary and Integrative Health note 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 any other herbal remedy. Diuretics may not be safe for people with kidney disease, for example.
Dandelion extract is available to purchase online.
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
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.
One way to manage water retention through the diet is by reducing salt intake.
Also, one study found that increasing the intake of magnesium and vitamin B-6 reduced symptoms of premenstrual syndrome, including edema. Dietary sources of magnesium include beans, nuts, whole grains, and leafy greens, while vitamin B-6 is present in bananas, walnuts, and potatoes.
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 healthful diet and getting plenty of exercise can help reduce the risk.
My mother is 78 years old, and she has swelling in her ankles and finds it hard to walk. Should she use diuretics?
She may benefit from seeing a physician, who will perform a series of tests to determine what the underlying issue might be. If she has a kidney issue, diuretics might cause serious harm.
Diuretics are useful for resolving short-term issues, but for symptoms such as this, it is best to consult with a doctor immediately.
In the short term, to relieve some of the pain, she can lie down with her feet on a pillow (raised above the heart). This may also relieve some of the swelling.Debra Sullivan, Ph.D., MSN, R.N., CNE, COI Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.