Fluid retention is a medical condition that occurs when the body is unable to express fluid, causing it to accumulate throughout the body or in a localized area. More properly known as edema, fluid retention is very common and can have a variety of causes and treatment approaches. It is often associated with pregnancy and hormonal changes caused by the use of hormonal contraceptives, along with circulatory problems, burns, certain medications, arthritis, and diseases of the liver, kidneys, heart, and lungs.
Water plays an important role in the body. It is found in the circulatory system and in the tissues of the body, often as a vehicle for nutrients or waste products. In healthy people, water moves through the body in the lymphatic system, which removes excess water while delivering fresh water, and the water is expressed through the kidneys as urine. The body uses several systems to keep the water level in balance, adjusting urine output to produce more or less urine as needed. When these systems are disrupted, fluid retention can occur.
The most common symptom of fluid retention is swelling that can be generalized or in a specific place, such as the legs. People may also feel achy and sore, with joint pain, stiffness, and weight gain. In pitting edema, when the swelling area is pressed, a small pit will form and fill slowly, while in non-pitting edema, the skin will bounce back after pressure.
Sometimes fluid retention is benign and will resolve on its own. For example, many women experience fluid retention during the phase of their menstrual cycle when estrogen increases, and the retained water is expressed later. In other cases, water retention may need to be treated to prevent further buildup and make the patient more comfortable. Treatment usually involves determining the underlying cause and addressing it.
People should not respond to fluid retention by drinking less water. Instead, they should see a doctor to find out why they are retaining water and what can be done to control it. For example, sometimes compression garments may be used to help the body express fluid, or a patient may vary the way they dress, sit, or stand to prevent fluid buildup. Pregnant women who spend a lot of time on their feet may find, for example, that fluid retention in the legs and ankles can be reduced by resting with the feet elevated.