What Causes Swelling?

Swelling is a natural process in the body that serves some very beneficial functions.  However, it is not very fun when we experience swelling.  With it come pain, discomfort, and the inability to move properly.

Let’s take a quick look at the processes that cause swelling so that we can better understand how to relieve it.

Lymphatic Diagram - Capillaries - Pain & Swelling Solutions of Albuquerque - blood vessels showing capillaries and lymphatic capillaries

Normal Tissue

Pictured here is a small piece of normal tissue made up of cells.  On either side are the arteries and veins that support the tissue. 

The purple sections between the arteries and veins are called capillaries.  Capillaries are special structures that allow nutrients from the blood to come out to feed tissues.

The green structure is the Lymphatic Capillary.  Lymphatic capillaries are responsible for draining the waste from the cell.

Cells Being Fed Animated GIF

Cells Being Fed

Notice the special vessels colored purple in the diagram. These are called capillaries, and they join the arteries and veins.  

Capillaries have little “windows” that allow substances to pass through from the blood stream to the cells. For our cells to get food, it is carried out of the bloodstream by fluid.

Our cells eat and poop just like we do, which leaves waste behind.  This waste and the fluid that carried the food to the cells are picked up by the lymphatic system. 

The Two Circulatory Systems

Circulatory System - Heart, Arteries,
Circulatory System – Heart, Arteries, & Veins
Lymphatic System
Lymphatic System

The Lymphatic System is a second circulatory system in the body.

Most of us learned about the primary circulatory system which includes the heart, arteries, and veins.

Note how the two systems look very similar next to one another.  This is not accidental.

Food is constantly being delivered to the tissues throughout the body, and the cells are constantly producing waste.

The fluid and waste have to go somewhere.  They can’t hang out in the tissues, so the lymphatic system picks them up and returns them to the heart, putting them back into the bloodstream.


swollen tissue microscopic view

Swollen Tissue

If, for some reason, the fluid can’t be removed from the tissue by the lymphatic system (pictured in green), swelling results.

Swelling can happen as a result of injury to the body – like slamming your hand in a car door or from surgery.  In this instance swelling acts like a natural splint to keep the body immobile so you can’t hurt yourself further.

Swelling can also be caused by a blocked lymphatic system (the drain).


Chronic Venous Insufficiency (CVI)

Properly functioning valves in veins.  Fluid cannot flow backwards.
Properly functioning valves in veins. Fluid cannot flow backwards.
Incompetent valves in this vein allow blood to reflux, or flow backward.
Incompetent valves in this vein allow blood to reflux, or flow backward.

Another cause of swelling is faulty valves in veins. When valves fail, gravity pulls the blood back down the leg.

This causes extra seepage of fluid out of the capillaries. When this happens, the lymphatic system can’t keep up with all of the extra fluid load and swelling results.

This condition is called Chronic Venous Insufficiency (a.k.a CVI or Ambulatory Venous Hypertension).  It is common and is often found in people who stand a great deal.


Lymphedema of the Left Leg
Lymphedema of the Left Leg

Lymphedema is a common type of swelling for people who have had cancer surgery.  It is caused when lymph nodes are removed either to test to see if cancer has spread (usually 1-3 nodes) or because cancer is found in the lymph nodes and they are all removed in an area.

This is like having a bridge collapse on a major interstate highway.  There is lots of traffic, but the cars can’t go past the damaged area.

You may be familiar with Lymphedema and just not know what it is called.  If you know someone who has had breast cancer and after their surgery they have to wear a special sleeve, this is to help prevent the swelling  from Lymphedema.

In rarer instances people can be born with a poorly formed lymphatic system which causes them to have Lymphedema.

Whatever the cause of your swelling,
there is help.

Pain & Swelling Solutions
can help you with your swelling. 

Therapy is painless and very effective.

Give us a call today! 

To learn more about how swelling can be reduced,
check out this page on Swelling Relief.