Why Do Our Bodies Swell?

Swelling, also known as edema, is the name for an increase in size, or change in shape, of an area of the body.

Swelling is a symptom of a variety of conditions, but there is always an underlying cause. Sometimes, the source of swelling can be serious and require immediate medical attention.

So, if you notice a swollen area on your body, it’s important to identify the reason.

Never Miss a Beat!

Get Healthy Tips Sent to Your Phone!

Message and data rates may apply. Text the word STOP to opt out and HELP for help. Click here to view the privacy and terms.

Types of Swelling

Body parts swell when body fluid is retained, or collects in a certain tissue, joint, or other area. Swelling can be internal or external, localized or generalized.

External swelling, typically affecting skin or muscles, is visible and usually due to an insect bite, illness, or injury. Internal swelling, which affects organs or other areas inside the body, usually has a more serious cause.

Localized swelling refers to swelling in just one area of the body, such as from a bee sting or an ankle sprain. Generalized swelling affects the whole body and is often the result of a major traumatic injury or allergic reaction.

Reasons for Swelling

  • Injury – Swelling often occurs at the site of injuries including strikes to the body, sprains, muscle strains, and bone fractures, because small tears in the surrounding blood vessels cause fluid to leak into the area.
  • Infection – Pockets of pus or other fluids may form at the site of an infection. This may actually help to resolve the infection, as extra fluids indicate the presence of infection-fighting white blood cells.
  • Allergic reaction – Large areas of the body may swell during an allergic reaction, which requires medical attention, especially if swelling of the face, tongue, or throat occurs.
  • Burns/chemical burns
  • Insect bites – Most insect stings and bites result in redness and swelling. If extreme swelling, redness, and itching occur, you may be having an allergic reaction to the bite.
  • Inflammation – Joints or tendons may swell after repeated motion or overuse.
  • Autoimmune/chronic diseases or circulation problems
  • Pregnancy – Pregnant women often experience swelling of the hands and feet, especially as pregnancy progresses.
  • Menstruation – Many women retain fluid during menstruation, resulting in swelling.
  • Standing, sitting, or walking for a long time in the heat may cause swelling of the lower legs.
  • Some medications
  • Surgery – Some swelling is normal after surgery at the site of an incision or affected area.
  • Other serious medical conditions like cirrhosis, liver/kidney disease or heart disease

How to Treat Swelling

Often, swelling will reduce on its own over time. You can take steps to help reduce swelling.

  • Get plenty of rest to protect the affected area.
  • Elevate the swollen area to above your heart.
  • For more serious swelling, the underlying cause may need to be treated by doctors. An exam and/or imaging tests can help determine issues.
  • Your doctor may be able to prescribe medication or recommend other methods to reduce the swelling.

If you notice sudden, extreme, or unexplained swelling, or if your swelling is due to a serious injury or medical condition, call your doctor or seek medical attention immediately or visit a UPMC Urgent Care location.

About UPMC

Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 800 doctors’ offices and outpatient centers, with locations throughout Pennsylvania, Maryland, New York, West Virginia, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. We are dedicated to providing Life Changing Medicine to our communities.