Diathermy is a therapeutic treatment most commonly prescribed for joint conditions such as rheumatoid arthritis and osteoarthritis. In diathermy, a high-frequency electric current is delivered via shortwave, microwave, or ultrasound to generate deep heat in body tissues.
The heat can be used to increase blood flow or to relieve pain.
Diathermy also can be used as a surgical tool to seal off blood vessels or destroy abnormal cells.
Diathermy uses an electric current to produce heat deep inside a targeted tissue. It can reach areas as deep as two inches from the skin’s surface.
The diathermy machine does not apply heat directly to the body. Instead, the current from the machine allows the body to generate heat from within the targeted tissue.
As the heat increases, it promotes blood flow. It also can help improve flexibility in stiff joints and connective tissue.
With decreased pain and inflammation, patients with arthritis can increase their range of motion. This may allow them to move more easily and participate in rehabilitation more comfortably.
In surgical procedures, a diathermy electrode can be applied to a blood vessel. The heat generated in the vessel will cause the blood to coagulate and the vessel to be cauterized (sealed).
Diathermy is also effective in removing abnormal growths, such as tumors, in procedures where traditional techniques are impractical. Surgical diathermy is used in many areas, including the prostate, bladder, cervix, brain, ovaries, bowels, eyes, and tonsils.
Diathermy often benefits patients who have pain from rheumatoid arthritis, osteoarthritis, or other musculoskeletal conditions. It is also used to treat discomfort from kidney stones or sinusitis.
However, if you have implanted metal devices, cancer, reduced skin sensation, peripheral vascular disease, or one of several other contraindications, you may not be an appropriate candidate for this treatment.
There are three main types of diathermy: shortwave, microwave, and ultrasound.
Shortwave diathermy uses high-frequency electromagnetic energy to generate heat. It may be applied in pulsed or continuous energy waves. It is used to treat pain from sinusitis, kidney stones, and pelvic infections. It is effective for conditions that cause pain and muscle spasms.
Microwave diathermy uses microwaves to generate heat in the body. It can be used to evenly warm deep tissues without heating the skin. Since it can’t penetrate deep muscles, it is best suited for areas that are closer to the skin, such as shoulders.
Ultrasound diathermy uses sound waves to treat deep tissues. Heat is generated by the vibration of the tissue. This promotes blood flow into the area. It is used for many types of musculoskeletal sprains, strains, and fractures.
The electromagnetic energy used in diathermy can cause extreme heat in metal devices such as bone pins, dental fillings, and metal sutures. This could cause burns in adjacent tissues.
During diathermy treatment, the patient becomes a part of the electrical field. Touching a bare metal object, such as a cabinet, during diathermy can cause a shock or burn.
Diathermy is administered by many types of health care providers, depending on the purpose of the treatment. Physicians, surgeons, dentists, physical therapists, chiropractors, and sports therapists use the technique.
Diathermy is usually part of a complete physical therapy or rehabilitative regimen. Frequency and length of treatments vary.
What Are the Steps?
Depending on the type of diathermy and the location of the affected area, the patient lies on a table or sits in a chair during the procedure.
Patients undergoing ultrasonic diathermy have a cream or gel applied to the affected area. In shortwave and microwave diathermy, the affected area may be wrapped in a towel to avoid direct contact between the skin and the electrodes.
During shortwave and microwave diathermy, two electrodes are positioned near the affected area. In ultrasound diathermy, a therapist moves a wand continuously over the affected area.
The patient is asked to remain still while the treatment is being administered. The patient feels a warm or tingling sensation during the treatment.
After diathermy, rehabilitative exercises are sometimes encouraged. These can make the most of the added range of motion and flexibility brought by the treatment.
Diathermy is used to produce heat in deep tissues in many parts of the body. In cases of injury or pain, the intense heat may provide pain relief and better flexibility. It can reduce inflammation, increase circulation, and accelerate healing.
Diathermy can be effective in providing some relief and treatment of symptoms related to:
- back pain
- muscle spasms
- sprains and strains
- bone injuries
In surgical uses, diathermy can be used to seal blood vessels and remove tumors or other abnormal growths. It can reduce blood loss and allow for reduced recovery times.
Patients with implanted metal devices, such as a pacemaker, a prosthesis, or an intrauterine device (IUD), may be at risk for injury if they undergo any type of diathermy. The risk of injury also exists in areas that are moist or filled with fluid.
Patients may be advised to avoid diathermy if they have any of the following conditions:
- implanted metal devices
- peripheral vascular disease
- tissue with restricted blood supply (ischemia)
- numbed or infected areas
- unhealed bones
- bleeding disorders
- severe heart, liver, or kidney conditions
- low skin sensation
- wound dressings
- areas of moist skin
Diathermy is not considered safe for certain areas of the body. These include the eyes, brain, ears, spinal cord, heart, reproductive organs, and genitalia.
All metal jewelry, clothing, and accessories must be removed before a diathermy session. You may be given a gown to wear during the procedure. You also may be asked to wear goggles.
After a diathermy treatment, the affected area may feel more flexible. The patient might be able to participate in physical therapy behaviors more comfortably and for a longer period of time.
The increased blood flow to the affected area may induce healing and tissue repair.
When used in surgery, diathermy may result in less blood loss and faster recovery times.
Treating pain and inflammation with heat can increase blood flow and make connective tissue more flexible. It can help minimize inflammation and reduce the incidence of fluid retention, or edema (The Merck Home Health Handbook, 2012).
By increasing blood flow to the site of an injury, the deep heat generated with diathermy can accelerate healing. It is most effective in joints, muscles, and tendons. However, the risk for burns is significant when used over moist or fluid-filled areas, or areas containing metal objects. Therefore, its use should be avoided in these circumstances (St. Vincent Health System).