What cells does diathermy destroy?

September 24, 2025 •

4 min read

By generating heat within tissues, diathermy is a powerful tool with varied applications. The heat destroys abnormal, infected, and cancerous tissue, but the specific cells affected depend on the treatment's intensity and purpose.

Quick Summary

Diathermy uses high-frequency energy, like electric currents or radio waves, to generate thermal energy that causes cell death through processes such as coagulation, dehydration, and vaporization. The technique targets specific cells in tumors, warts, and infected tissue, as well as cauterizing blood vessels.

Key Points

Diathermy Destroys Abnormal Cells: High-frequency electromagnetic energy is converted into heat to intentionally destroy cancerous cells, infected tissue, and warts.
Thermal Damage Mechanism: Cell death occurs at approximately 60°C, while coagulation and vaporization happen at higher temperatures, leading to cutting and cauterizing effects.
Surgical vs. Therapeutic Uses: Surgical diathermy targets and destroys cells, whereas therapeutic diathermy uses lower heat to promote healing and does not typically cause cell destruction.
Increased Proliferation for Healing: In some therapeutic cases, like pulsed shortwave diathermy, the treatment can actually increase the proliferation of beneficial cells like fibroblasts to aid in wound healing.
Risk of Burns to Healthy Cells: Improper use or the presence of metal implants can lead to uncontrolled heat generation, causing burns to healthy cells.
Targets Specific Tissues: The type of diathermy used (shortwave, microwave, ultrasound) determines the depth and type of tissue heated, allowing for selective targeting of cells.
High Frequency Prevents Nerve Damage: The very high frequency of the alternating current prevents the electrical stimulation of nerves and muscles, focusing the effect on thermal energy.

The Core Mechanism of Diathermy

Diathermy works by converting high-frequency electromagnetic energy into heat within the body's tissues. Unlike low-frequency household currents that can cause dangerous nerve stimulation and depolarization, the high-frequency alternating currents used in diathermy (typically 0.5-3 MHz) cause intracellular molecules to oscillate rapidly, generating friction and thus, heat. This rapid vibration bypasses the body's physiological electrical systems, making it safe for therapeutic use.

Temperature-Dependent Cellular Effects

The type and extent of cellular damage depend directly on the temperature reached at the treatment site. Diathermy can be controlled to achieve different outcomes:

Cell Death (Fulguration): When tissue temperature reaches approximately 60°C, cells die. This process, known as fulguration, is used to destroy abnormal cells.
Dehydration and Coagulation: Temperatures between 60°C and 99°C cause the tissue to dehydrate and the proteins to coagulate, effectively sealing blood vessels to achieve hemostasis and prevent bleeding.
Vaporization and Cutting: At temperatures around 100°C or higher, the water content within the cells rapidly vaporizes, causing the cells to burst. This precise thermal effect is used for cutting tissue during surgical procedures.

Targeted Cell Destruction in Surgical Diathermy

In surgical applications, also known as electrosurgery or electrodiathermy, the goal is typically to destroy specific, often abnormal, cell populations. The high current density at the tip of the electrode allows for a highly focused and localized thermal effect.

Cancer Cells: Diathermy is used in hyperthermia therapy to destroy malignant cells in tumors. For example, in lung cancer, a diathermy probe passed through a bronchoscope can destroy cancer cells blocking an airway. The heat causes irreversible thermal damage to the cancer cells, leading to their demise.
Warts and Other Abnormal Tissue: The thermal energy generated can also destroy warts and other benign skin lesions. The heat vaporizes the affected tissue, eliminating the abnormal cells.
Infected Tissue: For certain infections, diathermy can be used to destroy infected tissues, aiding in clearance and healing.
Blood Vessels: The primary use in many surgical fields is to cauterize blood vessels. The heat coagulates the blood and seals the vessel walls, preventing excessive bleeding.

Cellular Response in Therapeutic Diathermy

In physical and occupational therapy, diathermy is often used at lower, non-thermal or sub-thermal levels to relax muscles and promote healing, without deliberately destroying cells.

Enhanced Proliferation: Some forms, like pulsed shortwave diathermy (PSWD), are actually associated with increased rates of fibroblast and chondrocyte proliferation in vitro, which aids in wound healing and tissue repair. The mechanism is believed to involve improved blood flow and increased oxygenation, which facilitate the healing process.
Improved Blood Flow: By heating deeper tissues, therapeutic diathermy increases blood flow to the area. This helps to reduce inflammation, swelling, and pain, and can improve the mobility of recovering tissues.

Diathermy vs. Other Ablation Techniques

Diathermy is one of several techniques that use temperature to destroy or modify tissue. Its cellular effects are distinct from other modalities.


Feature	Diathermy (Thermal Ablation)	Cryoablation
Energy Source	High-frequency electromagnetic energy (radio waves, microwaves, electric currents)	Rapid cycles of extreme cold using cryo-probes
Mechanism of Cell Destruction	Thermal necrosis, dehydration, and vaporization	Cell damage from ice crystal formation and freeze-thaw cycles
Analgesic Effect	Can provide pain relief, though intense heat can be painful	Delivers additional pain management during the procedure due to freezing
Tissue Effect	Causes coagulation and charring; can create surgical smoke	Can disrupt pigment layers and lead to different types of scarring
Cavity Access	Can cause intracavitary scarring, potentially complicating future procedures	May offer different advantages regarding scarring depending on the application

Safety Considerations for Cell Protection

While diathermy is a precise tool for targeted cell destruction, safety precautions are crucial to protect unintended cells. The primary risk is burns from excessive or improperly focused heat. Contraindications include individuals with pacemakers or other implanted metal devices, as the electromagnetic fields can cause extreme, dangerous heating. It is also generally avoided in pregnant women and on areas with reduced sensation, infection, or malignancy (in some therapeutic contexts).

Consulting a qualified healthcare provider is essential to determine if diathermy is the right treatment for a specific condition, weighing the benefits of targeted cell destruction against potential risks. Learn more about medical applications of heat therapy at the National Cancer Institute.

Conclusion

Diathermy intentionally destroys specific cell types by using controlled thermal energy. In surgical procedures, it is deployed to eradicate abnormal and cancerous cells, cauterize blood vessels, and remove infected tissue, relying on a precise thermal effect to achieve its purpose. In contrast, therapeutic applications use lower, non-destructive heat levels to promote blood flow and healing, potentially even stimulating beneficial cells like fibroblasts. The success and safety of diathermy hinge on careful application to ensure that only the targeted cells are affected, sparing surrounding healthy tissue.

Frequently Asked Questions

The primary method diathermy uses to destroy cells is controlled thermal energy. It generates heat internally within the body's tissues by converting high-frequency electromagnetic waves into thermal energy, which causes cell death, coagulation, and vaporization.

Yes, if improperly applied, diathermy can cause thermal burns and destroy healthy cells. However, when used correctly by a trained professional, the procedure is designed to be highly targeted, focusing the destructive heat on specific, abnormal cells while sparing surrounding healthy tissue.

Yes, diathermy is a recognized form of hyperthermia therapy used to destroy cancer cells, for example, in tumors. The heat induces thermal damage that leads to the death of the malignant cells.

Surgical diathermy uses high heat to deliberately destroy and cut through cells, coagulate blood vessels, or remove abnormal tissue. Therapeutic diathermy uses lower, non-destructive levels of heat to increase blood flow, relax muscles, and promote healing without destroying cells.

Diathermy typically causes cell death (fulguration) when the tissue temperature reaches approximately 60°C. Higher temperatures, around 100°C, cause vaporization for cutting tissue.

When used for warts, diathermy targets and destroys the epidermal cells of the wart tissue. The heat vaporizes the affected tissue, eliminating the abnormal growth.

No, diathermy is not safe for everyone. It is contraindicated for individuals with metal implants like pacemakers or joint prosthetics, pregnant women, and people with certain severe conditions, as it poses a burn risk.