What is swelling?

Swelling is the body’s reaction to an injury or other disease. Swelling occurs when a body part increases in size or if there is a buildup of fluid in the organs, skin or other parts of the body.

Swelling in the tissue alone is called edema.

Most people will experience swelling at some point in their lives. Mild swelling can be attributed to heat or sitting or standing in a position too long.

Causes of swelling

The causes of swelling are categorized as localized (one location) or generalized (the entire body).

Causes of localized swelling

Localized swelling can occur due to a variety of conditions such as:

  • Illnesses
  • Injuries
  • Infection
  • Menstruation
  • Fluid retention 
  • Rash
  • Hives
  • Hematomas or bruising
  • Burns

Causes of generalized swelling

Generalized swelling can occur due to the following causes:

  • Allergic reactions from insect bites or food
  • Autoimmune diseases such as lupus, rheumatoid arthritis or scleroderma
  • Medicines — also known as a drug allergy
  • Accumulation of fluid in the abdomen

If you have internal swelling, it could be a side effect of medication or a serious traumatic injury.

Risk factors for swelling

Risk factors of swelling relate to the conditions that cause the swelling. For example, if your swelling is caused by a broken bone, a risk factor is participating in activities that could cause a broken bone.

Risk factors of edema are:

  • Lymphedema
  • Diuretic
  • Angioedema
  • Nephrotic syndrome
  • Peripheral edema

Symptoms of swelling

Symptoms of swelling differ based upon where the swelling occurs, either externally or internally.

Symptoms of external swelling

The initial sign of external swelling is typically raised or enlarged skin around an injury. In some cases, the enlargement is due to fluid buildup in the affected area.

Symptoms of internal swelling

Internal swelling signs and symptoms include:

  • Vomiting
  • Dizziness
  • Fever
  • Fatigue
  • Insomnia
  • Pain
  • Flu-like symptoms

Diagnosis of swelling

Typically, your primary care doctor can diagnose swelling as well as the cause of the swelling during a physical exam. If further testing is needed, an ultrasound, computed tomography test (CT scan) or magnetic resonance imaging (MRI) can provide images to aid in the diagnosis.

Diagnostic imaging tests can show inflammation on the muscles or tissues as well as bone fractures.  Further, it can show if you have blockages in the vessels or are retaining fluid.

If you have unexplained swelling, rapid weight gain and pain, visit the closest Mercy Health ER right away.

Treatment for swelling

Your doctor will treat the cause of your swelling. For example, if you have a snake bite, he or she may give you an adrenaline shot and follow the treatment protocol for snake bites.

Mild rashes, insect bites or hives can be treated at home with over-the-counter medications.

For more severe swelling, your primary care doctor can prescribe medication or topical steroids to relieve inflammation and swelling.

Find a primary care doctor nearby

Mercy Health locations that can treat you