If you have sprained an ankle or twisted a knee, you know something about localized swelling. In this article, we’ll explain what swelling is, cover some of the common reasons for swelling, and describe how the body works to reduce swelling. We’ll also discuss a type of therapy that can help reduce some types of chronic swelling.
Swelling, or edema, is a condition of excessive accumulation of tissue fluid. General swelling has many causes: heart, kidney or liver problems; hormonal imbalances; drug reactions, and allergies. Now let’s focus on localized edemas such as those caused by injury (sprains, fractures, burns), surgeries such as mastectomies, or treatments such as radiation.
To understand swelling, we need to take a quick look at the anatomy showing how fluid moves through the body. The heart pumps blood through the body via large vessels called arteries. Arteries break to smaller and smaller vessels until they become microscopic capillaries, which surround individual cells. The cells receive nutrients and oxygen from the blood. Most of the blood returns to the heart through the veins, but some fluid and proteins trapped outside the capillaries must find their way back to the heart in a passive circulatory system called the lymphatic system. Just as perimeter drains around a house collect water and move it away, the tiny lymphatic vessels collect excess fluid, toxins and proteins from the tissue. This fluid is called lymph.
As the vessels become progressively larger, they enter lymph nodes and the lymph is filtered of impurities and toxins. Then the lymphatic vessels continue to their final destination, the thoracic ducts located just above the collarbones. All lymphatic circulation, totaling about 1½ to 3½ liters of lymph each day, must empty into these ducts so that the lymph can complete its return journey to the heart.
Without a properly functioning lymphatic system, our bodies couldn’t detoxify and regenerate tissues, filter out foreign substances or maintain a healthy immune system.
In swelling resulting from an injury, excessive fluid leaks from the cells and out of damaged capillaries in the traumatized area. This excess overloads the lymphatic vessels and fluid begins to pool. Areas farthest away from the heart, such as the ankle, are particularly affected, since the passive lymphatic system must fight against gravity to return fluid to the heart. This is why, when in a reclined position, elevating a swollen limb above heart level helps to decrease swelling. In some cases, however, this type of swelling can become chronic.
In other cases, lymphatic vessels and lymph nodes can be damaged by radiation treatment or surgery, and lymph can pool. This condition is often seen in an arm or leg and it is called lymphedema.
Specialized techniques to relieve lymphedema have been known since the late 1800’s. Many European physical therapists have practiced manual lymphatic drainage techniques since the 1930’s. The technique has gained awareness and acceptance in the United States during the last 10 years because its effectiveness is well documented. Clinicians who have taken advanced training can become certified in lymphatic drainage therapy. Most certified practitioners either practice in rehabilitation hospitals or private clinics specializing in hands-on therapy.
Benefits of lymph drainage therapy include rerouting stagnant fluid back to the general circulation when lymphatic vessels have been damaged. This helps both to drain toxins from a particular area and promote tissue regeneration and healing. The application of lymph drainage therapy is especially important in a scarred area, or at the site of surgery or fractures.
Lymphatic drainage therapy also stimulates the immune system, helping with chronic or subacute inflammatory processes such as sinusitis, arthritis, and chronic fatigue. In addition, it can help stimulate the part of the nervous system that produces a calming effect on the body, which reduces the triggering of the fight or flight response. This can help in dealing with stress, depression and sleeping disorders. Voluntary and involuntary muscle spasms are also reduced, which can prove helpful in constipation and other muscle-related problems.
Often, when an abrupt change such as swelling occurs in your body, it can help to have a little familiarity with some causes, functions, purposes and results of swelling because you are witnessing human biology in action.