Whether it's caused by a bee sting or a sprained ankle, everyone has experienced swelling at one time or another. Swelling, also known as edema, is part of the body's inflammatory process, which helps the body when it becomes injured. Knowing how swelling occurs may make it easier to tolerate when it happens to you.
Our bodies undergo the inflammatory process virtually any time an injury or tissue damage occurs. Along with redness, heat and pain, swelling is a sign of the inflammatory process at work. When part of the body is injured, chemicals are released that act on our smallest blood vessels, called the capillaries. These chemicals cause the capillaries to vasodilate, or widen, and thus leads to both an increase in blood flow and a leakage of fluid into the injured area. It also allows infection-fighting cells to enter the injury site. Swelling occurs as a result of this fluid leakage into the surrounding tissues. Although the inflammatory process is beneficial in terms of helping the body to heal, sometimes localized swelling is a less helpful side-effect, so it is often treated by the use of ice, heat, compression, elevation and non-steroidal or steroidal anti-inflammatory medications.
Swelling can also occur systemically, or throughout the entire body. Then it's generally referred to as edema. It occurs basically the same way as localized swelling, but involves larger areas of the body. Typically, when generalized edema occurs, it involves not only temporary leakage of fluid into the tissue as a response to injury, but also a problem with the fluid being reabsorbed by the blood vessels. The lymphatic system, which is also responsible for absorbing fluid throughout the body, may also be malfunctioning, leading to further swelling issues. Swelling of this nature is usually secondary to a more serious medical condition or illness, such as pregnancy, cancer or kidney failure.