The Effects of Manual Lymphatic Drainage

Manual Lymphatic Drainage (MLD)  is a light, hands-on modality applied by Registered Massage Therapists (RMTs) using superficial pressure with the intention of promoting the circulation of lymph within the body’s specialized lymphatic circulatory system. 

Research over the last few decades has found that the lymphatic system is part of the body’s innate immunity meaning that it’s part of an in-born system that serves as one of the body’s primary defense mechanisms again the invasion of antigens and the spread of infection. At its origin lymph can be found in blood while it circulates along with red and white cells, proteins such as albumin, and the nutrients associated with the everyday physiological functions of the body. As it travels from the heart and through arteries towards the capillary beds, it becomes separated from blood as it’s pulled out of the bloodstream and through the arterial walls during a process called osmosis. The lymph seeps into the interstitial cracks and crevices of the microscopic spaces between cells where it bathes the tissues and washes away cellular debris and other metabolites and is filtered by a network of nodes. Along its journey the majority of the lymphatic fluid ends up rejoining the blood again at the venous end of the capillary beds, however, there is a small portion, about 2.4 liters per day, which ends up traveling through a network of ducts and nodes where it will eventually rejoin the blood in the heart via the Thoracic and Right Lymphatic Ducts.

The lymphatic system is one of the body’s primary methods of defending itself from foreign bacteria, viruses, as well as various other pathogens, and pre-cancerous cells. The body’s T cells which are synonymous with natural immunity originate within the bone marrow of the long bones and migrate to various nodes within the lymphatic system such as the thymus, and other central collections of nodes within the axillary and inguinal regions of the body. It has been shown that MLD performed by a trained professional like an RMT can assist with the movement of a fluid such as lymph by coxing it back into the body’s systemic circulation using a combination of opening high-density nodal areas using counterclockwise “opening” motions first performed at “terminus” located above the clavicle, and then performing a “pumping” motion over the top of the intended nodal destination in order to prepare the area to receive an influx of lymph from areas of congestion.   

MLD techniques were originally discovered and developed by the legendary physiotherapist, Emil Vodder in the 1930s. Since then numerous research studies have confirmed the efficacy of MLD treatments and found that it is indeed useful in encouraging the flow of lymphatic fluid and reducing certain types of edema. The lymphatic system is passive in that it relies primarily on surrounding skeletal muscles and the action of the diaphragm to move lymphatic fluid through its capillaries, nodes, and ducts. The larger abdominal and thoracic ducts have contractile abilities and recent studies may indicate that the superficial lymphatic capillaries also have a minor capability to contract. It is for this reason that RMTs must sometimes manually assist in the drainage of lymphatic fluid in order to help reduce edema by gently coaxing the fluid back toward the central nodal congregations. In addition to reducing edema, and the relatively light pressure used, this technique has also been shown to be beneficial in decreasing pain while also promoting the calming effects of the parasympathetic nervous system. 

The term “Edema” is often used to describe a local or general accumulation of fluid in the interstitial spaces surrounding capillary beds. When this happens, it’s usually part of the body’s natural immune system response to the presence of histamines in the blood, but can also be a sign of major systemic diseases such as ventricular failure or the obstruction of lymphatic vessels. It is for this reason that it’s important to investigate and understand the causes surrounding the accumulation of edema and consult with a medical professional before beginning manual lymphatic drainage as a treatment modality.   

During the application of MLD, the therapist’s hands must be soft and relaxed as too much pressure will result in the temporary collapse of the capillary beds and ultimately impedes lymphatic flow. When implementing an MLD treatment the strokes are often unidirectional and overlapping in a centripetal manner which assists flow through lymphatic nodes and vessels along its journey towards the lymphatic ducts and back into the heart. 

With edema resulting from acute or subacute trauma, manual lymphatic drainage techniques are also useful in reducing the formation of scar tissue. This is accomplished by the removal of fibrin from the initial lymphatics. Edema resulting from connective tissue restrictions such as post-surgical scarring can also be treated. People with lymphedema experience an increase in urine output and concentrations of histamine within the urine, corticosteroids, and noradrenaline also increased after lymphatic drainage, which suggests the technique improves the clearance of these substances from edematous tissues. 

Common Causes of Edema: 

• Increased permeability of capillaries resulting from inflammation, tissue trauma, burns, and general immune system responses. 
• Obstruction of lymphatic flow due to infection, parasites, disease, surgical procedures such as the removal of lymph nodes, or radiation treatment that can lead to retention of plasma proteins which have an osmotic effect drawing excess lymph out of the circulatory system. 
• Increased venous or capillary pressure due to heart/ventricular failure, thrombophlebitis (blood clots), pregnancy, and allergies. 
• Prolonged sitting or standing may also contribute to the retention of sodium molecules in the extremities which can act to retain fluid as well. 
• A decreased presence of plasma proteins which is seen with liver and kidney disease as well as starvation or excessive burns can cause an increase in the volume of fluid in certain areas which overwhelms the body’s lymphatic circulatory system.  
• Unfortunately, edema may also result on its own, or as a result of a combination of any of the reasons listed above, which is why it is so important to consult with your doctor if you suspect that there may be a problem with the circulation of lymphatic fluid in your body.   

Classifications of Edema: 

• Acute edema is often characterized by the feeling of pain or discomfort or fullness following injury or trauma to soft tissue or joints. There may be a sensation of heat in the area followed by redness and a decrease in the range of motion of the affected region. 
• The Early Sub-Acute stage refers to the presence of edema several days after the initial trauma or injury to the area. During this time there is typically a small decrease in the amount of fluid localized to the area of injury as well as some improvement with a range of motion and a reduction in redness. Hematomas or large sub-cutaneous bruises may also become evident during this time, and the area is often still quite tender to the touch. 
• Chronic lymphedema refers to the ongoing accumulation of interstitial fluid within the tissues of the body.   
• Local lymphedema usually involves the whole limb which is distal to the site of an injury. 
• General system lymphedema affects the entire body and can be characterized by puffy or congested tissue and may indicate the presence of a serious disease or infection. 
• Surgical lymphedema may result anywhere from weeks to years following a surgical procedure.    
• Non-Pitted Edema is firm and discolored and results from the coagulation of plasma proteins in the interstitial spaces following tissue trauma or localized infections. 
• Pitting Edema is “boggy” to the touch in that the tissue retains the indentation on a finger after the pressure is removed from the area. The type of edema is usually associated with chronic pathology when the fluid accumulation rate exceeds that of the venous filtration rate.  

Contraindications to MLD, and the Treatment of Local Edema:

• Treatment of an acute injury is not advised (Rest, ice, and elevation is key during this stage)
• Treatment distal to the site of inflammation may increase congestion 
• Warm or hot hydrotherapy immediately proximal to inflamed tissue 
• Acute injuries or conditions associated with bacterial or viral infections 
• Recent blood clots, embolism, thrombosis 
• Kidney pathologies associated with low protein levels 
• Starvation associated conditions 
• Metastasizing neoplasms or tumors including melanoma 
• Lymphatic obstruction due to parasitic invasion 
• Presence of tuberculosis bacteria 
• Toxoplasmosis associated with lung infections 
• Chronic congestive heart failure  

In treating early sub-acute, or chronic edema, nodal pumping or compression is applied to the lymphatic nodes of the most proximal part of the limb that has the edematous tissue. These nodes are also closest to the thoracic and right lymphatic ducts, which return lymph to the venous system. In the arm, these are the axillary lymph nodes. In the leg, these are the inguinal lymph nodes. 

The article was created by Ryan Walsworth RMT on 11.01.2022

Information for this article was taken from Rattray Clinical Massage Therapy, Chapters on MLD + Edema pages 40 + 218-220