The currents used for the treatment purpose is called therapeutic currents. According to the difference in frequencies, the currents can be divided into the following three types.

  1. Low frequency currents
  2. Medium frequency currents
  3. High frequency currents

Low frequency currents:

The current which has frequency ranging from 1 – 1000 Hz is called low frequency current.

Examples:

TENS, Galvanic current, Faradic current

Medium frequency currents:

The currents which have frequency distribution ranging from 1000 – 10000 Hz are called medium frequency currents.

Examples:

Interferential therapy, Russian current

High Frequency currents:

The currents having frequency above 10000 Hz are called high frequency currents.

Examples:

Short Wave Diathermy, Microwave Diathermy, Infrared Radiations, Ultrasound.