Several factors may contribute to inflammation including injury, tissue damage, a poor localized circulation with the formation of edema. Inflammation causes pain. Swelling and bruising is an inflammation and discoloration of soft tissue caused by an impact injury or trauma. It can also result from surgery.

Tissue cells are inherently like tiny, electrically charged machines. When a cell is traumatized, the cell’s electrical charge is diminished; this causes normal cell functions and operations to shut down. Cells that are scarred or fibrotic with adhesions have a TMP charge of approximately -15 mV, degenerative or immune-compromised cells average -30 mV, both low TMPs. With the raised TMP, the body releases chemical signals that cause inflammation swelling and bruising resulting in pain and inhibiting the cell communication pathways necessary for healing to begin. Numerous clinical studies have demonstrated that PEMF therapy has been successful in reducing inflammation. PEMF therapy treats the cellular source of swelling by recharging the cells with a mild electromagnetic current. This stops the release of pain and inflammatory mediators, reduces inflammatory fluids and allows an increase in blood flow, therefore increased oxygen intake, to help the cells heal faster with less swelling, pain and bruising.

The effect of wound healing electromagnetic fields on inflammatory cytokine gene expression in rats was studied by Jasti et al. in 2001 who state: “Inflammation is characterized by massive infiltration of T lymphocytes, neutrophils and macrophages into the damaged tissue. These inflammatory cells produce a variety of cytokines, which are the cellular regulators of inflammation.” In a study on Low frequency PEMF-a viable alternative therapy for arthritis published in 2009, Ganesan et al. (Department of Biotechnology, Chennai, India) declare: “PEMF for arthritis cure has conclusively shown that PEMF not only alleviates the pain in the arthritis condition but it also affords chondroprotection, exerts anti-inflammatory action and helps in bone remodeling, and this could be developed as a viable alternative for arthritis therapy.”
Damaged cells are also energy deficient; thus they have low oxygen levels, are high in sodium levels, and have a faltered electrochemical gradient. By inducing a mild electrical current into damaged cells, PEMF therapy slows or stops the release of pain and inflammatory mediators, increases blood flow, and reestablishes normal cell interaction. PEMF stimulates and restores the electrochemical gradient, the cell starts pumping sodium out, potassium enters the cell, the swelling resolves, oxygen starts flowing back in, and pain improves. Due to the density of the cell tissue, change requires stronger pulsed magnetic fields to be able to restore the healthy TMP to its optimal -70 mV.
Several factors influence tissue inflammation and the processes by which PEMF therapy operates to reduce inflammation include complex mechanical, chemical, electrical and magnetic processes along with increased circulation, oxygenation and cellular activity. With reduced inflammation, pain decreases and faster tissue healing occurs.

The Elsevier Journal of Biomedicine & Pharmacotherapy (2005) publication:
Effects of pulsed electromagnetic fields on articular hyaline cartilage: review of experimental and clinical studies by M. Fini. G. Giavaresi, A. Carpi, A. Nicolini, S. Setti, R. Giardino (Experimental Surgery Department, Research Institute Codivilla-Putti-Rizzoli, Orthopedic Institute, via di Barbiano 1/10, 40136 Bologna, Italy, Department of Reproduction and Aging, University of Pisa, Pisa, Italy, Department of Internal Medicine, University of Pisa, Pisa, Italy, igea SRL, Carpi, Modena, Italy) states: “Newer concepts on osteoarthritis (OA) pathogenesis are related to the role of inflammation that is now well accepted as a feature in OA. Synovitis is common in advanced age involving infiltration of activated B cells and T lymphocytes and the expression of pro-inflammatory cytokines and chemokines is observed in patients with OA in the joints of OA patients and animals. With regards to this, IL-1, TNFæ, IL-6, IL-18, IL-17 and leukemia inhibitory factor (LIF) appear to be more relevant to the disease. These catabolic cytokines lead to the destruction of joint tissue by stimulating cartilage PG resorption, MMP synthesis and nitric oxide production. The purine base adenosine has been shown to limit inflammation through receptor (i.e. A2a)-mediated regulation and suppressing pro-inflammatory cytokines synthesis (TNFæ, IL-8, IL-2, IL-6). Adenosine has been reported to reduce inflammation and swelling in several in vivo models of inflammation and also in adjuvant-induced and septic arthritis in animals. So, a therapy combining an anabolic effect on chondrocytes, a catabolic cytokine blockage, a stimulatory effect on anabolic cytokine production and one that is able to counteract the inflammatory process would be extremely useful for OA treatment. In vitro studies showed that chondrocyte proliferation and matrix synthesis are significantly enhanced by PEMF stimulation, when investigating also the conditions affecting the PEMF action. A part the importance of physical properties of the fields used (intensity, frequency, impulse amplitude, etc.) and the exposure time, the availability of growth factors, environmental constrictions and the maintenance of the native-cell matrix interactions seem to be fundamental in driving the PEMF-induced stimulation. In particular, the interaction between cell membrane receptors and mitogens seems to be one of the molecular events affected by PEMFs. These data are in agreement with results of in vivo studies with a decalcified bone matrixinduced endochondral ossification model and showing that the stimulation of TGF-1 may be a mechanism through which PEMFs affect complex tissue behavior and through which the effects of PEMFs may be amplified. In addition, PEMFs are reported to up-regulate mRNA levels for, and protein synthesis of, growth factors resulting in the synthesis of ECM proteins and acceleration of tissue repair. As far as inflammation is concerned, IL-1 is present in high amounts in OA cartilage and is considered to be one of the main catabolic factors involved in the cartilage matrix degradation associated with OA. As previously mentioned, PEMFs in vitro were able to counterbalance efficiently the cartilage degradation induced by the catabolic cytokine”.

As cited above, many studies lead to the conclusion that PEMF therapy is effective and reduces inflammation.