Diathermy: what is it and how does it help patients?

Every physiotherapist knows the positive effects heat can have on the human body. That is why it has been used to support physiotherapy treatments for such a long time. Heat can be applied both superficially and in depth. Superficial heat treatment includes a hot pack, paraffin wrap, or the use of an infrared lamp. In these applications, heat penetrates the body to a maximum of 1 cm. Deep heat treatments allow heat to penetrate the body to a depth of as much as 3 to 5 cm. Not only do short-wave diathermy, ultrasound or TECAR therapy meet such requirements but all of these treatments form part of the umbrella term “diathermy”. That is precisely what this blog is about: diathermy. What is it exactly and how can it help your patients?

What is diathermy?

In a nutshell, diathermy is the production of “internal heat through strong high-frequency electrical currents”. In other words, heat generation in the body through electrical and/or electromagnetic currents. This electromagnetic energy is non-ionising (meaning it does not affect cell structure). We describe various forms of diathermy below.

Short-wave diathermy

Short-wave diathermy is the medical application of electromagnetic energy. The waves penetrate deeply into the body and can have thermal effects (improving blood flow) and a-thermal effects (at cellular level). Collectively, both effects can have a significant physiological impact, which is why this method is suitable for various conditions. The treatment frequency is usually 27.12 MHz. However, due to the knowledge required to apply the treatment and the inherent contraindications, for both patient and therapist, this type of diathermy is used less often.

Ultrasound therapy

Ultrasound therapy is a medical treatment that uses mechanical vibrations with a frequency of more than 20 kHz. When applied continuously, mechanical vibrations in the tissue essentially create a thermal effect, which reduces pain, promotes muscle relaxation and recovery. In addition, deeper situated ligament inflammation (up to 2 cm) can easily be dealt with. As a result, oedema and pain may decrease when treated with ultrasound therapy. This type of treatment uses a treatment frequency of 1 or 3 MHz. 

TECAR therapy

TECAR therapy combines contact diathermy and electrotherapy and is a distinct form of long-wave diathermy, the most penetrating kind of diathermy. This application stimulates blood circulation and the body’s healing process when treating acute and chronic conditions. The therapeutic wavelength spectrum ranges from 300 KHz to 1.2 MHz.

Effects of diathermy on the human body

Primary physiological effects The primary physiological effects and benefits of using diathermy include:

  • improved circulation and blood flow
  • improved metabolism
  • increased muscle temperature
  • increased tissue temperature
  • pain modulation
  • reduction of tissue stiffness
  • muscle relaxation

Indirectly, these effects can also improve the range of motion of the joints.

Which ailments benefit most from diathermy?

Thanks to its extensive physiological effects, diathermy can be used for a wide range of complaints or conditions, including:

  • bruises and sprains
  • fractures
  • tendonitis, bursitis, capsulitis, and joint inflammation
  • muscle and tendon disorders
  • vascular and lymphatic system disorders
  • neuropathies
  • scar tissue
  • post-surgery rehabilitation
  • pelvic floor rehabilitation
  • acute and chronic pain
  • poor circulation

Of course, diathermy can be of advantage to other physiotherapy treatment techniques, such as manual therapy, remedial therapy, fascia therapy, percutaneous electrolysis therapy, and shockwave therapy.

Patient experiences

We spoke with three patients wanting to share their experiences with diathermy.

Irene’s experience with TECAR therapy

Irene suffered from uncontrollable calf cramps and was under consideration for a baclofen pump. However, eight weeks of intensive treatment with TECAR therapy proved to be the solution to her ailments: “My doctor stopped the medication for my muscle cramps altogether after my treatment with your miracle machine. Thank you!”

Henry’s experience with ultrasound therapy

Henry had a good experience with ultrasound therapy: “I thought I had torn or sprained ligaments in my knee. The ultrasound treatment quickly revealed that it was far more likely to be persistent inflammation. The pain and instability are a lot better now.” 

Charles’ experience with short-wave diathermy

Short-wave diathermy is perfect for treating knee osteoarthritis during the subacute to the chronic phase. It accelerates the processes of functional recovery and pain reduction. Charles agrees: “When your joints start to squeak and creak a bit, it is nice to be able to rely on a physiotherapist who knows what equipment to use. The deep heat therapy works great for my knee osteoarthritis.”

Diathermy in your practice

If you want to use diathermy in your practice, you need the right equipment. Choosing a suitable device helps physiotherapists deliver efficient and successful treatments. 

Short-wave diathermy equipment

The Gymna 500+ short-wave treatment device has a straightforward user interface with a quick set-up and accommodates both continuous and pulsed short-wave therapy. What’s more, the intensity can be fully adjusted according to your patients’ needs.

Ultrasound therapy equipment 

The Gymna 400 combines intelligent solutions with state-of-the-art technology. The device is always up to date, as new scientific developments are constantly being added through regular updates. As a result, treatments are always evidence-based. In addition, the full-colour touchscreen makes the device easy to operate. Finally, the Guided Therapy System (GTS) helps the therapist select a proper treatment.

TECAR therapy equipment 

The Gymna Care 300 works with an app on the iPad included with the device, which means that your device is always up to date. The device accommodates a pulsed mode for a less pronounced temperature increase, which is crucial for treatments in a more acute phase. Moreover, the device provides five pre-set operating frequencies between 300 kHz and 1MHz, allowing the therapist to select the best possible frequency for each patient. Furthermore, the device comes with many accessories, giving it many applications.

Would you like to use diathermy in your practice?

Scientific literature12 teaches us that diathermy administered by a skilled therapist may be of great value to achieve the desired  results as a primary therapeutical strategy or as part of a combined treatment plan. Would you like to introduce diathermy treatments in your practice? Or would you like to take your diathermy treatments to the next level? We are happy to discuss your options with you.


1Mazurek B, Clinical application of impact capacitive – resistive electric transfer 448 khz on human cells. International Journal of Biomedical Science and Engineering. 2018; 6(3): 65-69. doi: 10.11648/j.ijbse.20180603.12 2https://www.webmd.com/pain-management/what-is-diathermy