swelling
Meaning of swelling: An increase in size that says nothing about the contents, which may be fluid, blood, pus, inflamed tissue or new growth.
Definition of swelling
Swelling is enlargement of a part of the body beyond its normal size, from something accumulating within it or from the tissue itself expanding. Fluid in the spaces between cells, blood from a damaged vessel, pus from infection, inflamed tissue and abnormal growths all produce it. Swelling may be confined to one spot, affect a whole limb, or appear across the body at once.
Is swelling the same as edema?
No. Edema means fluid gathered in the spaces between cells, which is one cause of swelling among several. A swollen ankle after a twist holds blood and inflammatory fluid, a swollen knee holds fluid inside the joint cavity, a swollen gland holds multiplying cells, and a swollen abdomen may hold gas, fluid or a mass. Treating the two words as interchangeable narrows the field before anything has actually been established.
What does pitting mean?
That steady pressure on the swelling leaves a dent which fills in slowly afterward. Pitting shows the fluid is mostly water and can be pushed aside for a moment. Swelling that does not pit holds something less mobile: protein-rich fluid trapped by blocked lymph drainage, fat, or thickened tissue. Where the swelling settles also carries information, since fluid held back by the circulation collects wherever gravity takes it, gathering around the ankles by evening and over the lower back in someone lying down.
What distinguishes inflammatory swelling?
Warmth, redness and tenderness accompanying it, along with reduced use of the part. Inflammation widens local vessels and makes their walls leaky, so fluid and white cells enter the tissue deliberately rather than passively. That combination separates an infected or inflamed joint from one swollen by long-standing fluid, which is cool and often painless.
| Type | What is inside | How it behaves |
|---|---|---|
| Edema | Watery fluid between the cells | Pits under steady pressure, worse in the evening |
| Lymphedema | Protein-rich fluid held back by blocked drainage | Firm, pits poorly, and the skin thickens over time |
| Inflammatory swelling | Fluid and immune cells drawn into the tissue | Warm, red and tender |
| Hematoma | Blood from a broken vessel | A firm lump, discoloring as it resolves |
| Effusion | Fluid inside a joint or body cavity | The joint feels tight and bends less far |
Also known as
Used in a sentence
Swelling of the lower legs was noted to be pitting and symmetrical.
Good to know
Swelling and edema are not interchangeable, since edema names fluid in the spaces between cells and is only one of the things that makes a body part larger.