What is phase angle?

- The seca mBCA uses the Bio-electrical Impedance Analysis (BIA) to non-invasively assess body composition - the measurement of body fat in relation to lean body mass. It is an essential tool and integral part of any comprehensive health and nutrition assessment. Compared to the Body Mass Index (BMI), which is dependent on weight and height alone, and because of this the assumptions of lean mass and adipose tissue distribution are not always accurate - BIA is much more precise and significant.

One key parameter that the seca mBCA measures is the phase angle. It is an indicator of overall health, metabolic activity and nutritional status.

To understand the phase angle, it is necessary to take a closer look at the BIA’s components. Electrodes transmit a low alternating current through the patient’s body while simultaneously capturing the total physical resistance, als known as the impedance, which occurs in the tissue. The impedance is dependent on the measured resistance from body water that contains electrolytes, also known as resistance (R), as well as on the capacitive resistance which is generated by cell membranes and known as reactance (Xc).

Picture: The phase angle is determined by way of resistance (water resistance) and reactance (cell resistance).

What the phase angle means?

The alternating current and voltage periodically change their polarity and direction. For example, electricity in our homes displays a sinus curve-shaped course. Our body liquids work as simple electrical conductors. They contrast the current flow with an ohmic resistance, where electricity and voltage proceed in the same time rhythm, crossing the zero line at the exact same time.

The cell membranes, however, reveal that the electricity is faster than the voltage. This is a result of the membranes in our cells changing and discharged like a capacitor under an alternating current. A phase shift between electricity and voltage is induced through the chronological delay. This shift can be measured in degrees and is then referred to as the "phase angle".

Which statements can be made with a phase angle?

The phase angle is an important parameter for estimating an organism’s health status as well as the nutritional state of cells. The higher the phase angle, the more imperishable and healthy the cell membranes are. Standard ranges for a phase angle depend on gender (male>female), age (with elderly patients the phase angle reduces in size), ethnicity (the Japanese, for example, have smaller phase angles than Caucasians), body height (the phase angle reduces in size, the taller the person), the position while taking measurements (the phase angle will be larger when determined from a lying patient, whereas a standing patient will have a smaller phase angle) and of course the device taking the measurement.

A large phase angle can be a sign of cell membranes in good condition and a large amount of muscular mass, but it can also signify a high ratio of fat. With the assistance of measuring additional parameters with the seca mBCA, these tissues can be differentiated precisely differentiated.

Small phase angles can point to general cell damage, muscle atrophy through malnourishment or pathological weight-loss (cachexie) from tumor afflictions or other illnesses.

The phase angle is also dependent on the following parameters:

With the help of the seca mBCA devices, body compositions and phase angles can be quickly and precisely determined. Body composition is of high value in many fields of application, the phase angle in particular offers important information on an organism’s general condition. Thanks to the devices’ user-friendly conceptual design, the measuring data for phase angles are accurately processed and can be easily interpreted from the seca mBCA display. Finally, the phase angle is an important parameter for the clinical and ambulant sector, offering valuable information on a patient’s health status.  

Contact.

seca press service.

Are you from the press and would like to request information about our company or our products? You can contact our press office directly using the e-mail form.

The fields marked with an asterisk (*) must be filled out. All other information is provided voluntarily.

News Form

Individual Subject (grey)
standard fields (grey)

Our privacy policy information applies.

Submit field