How much harm does ultrasound do to the body?

The principle of ultrasound is to use the physical principle of sound waves, frequency>20000Hz for ultrasound, medical ultrasound frequency of 1 ~ 15MHz. ultrasound is the essence of sound waves, i.e., mechanical waves, so it does not have the harm of ionizing radiation, and at present has not been found that ultrasound examination of the human body has been harmful.

The biological effect of ultrasound on the human body is related to the ultrasound power and exposure time. Low-power ultrasound, limited exposure time, will not produce significant biological effects. Although high-intensity ultrasound (>5W/cm2) is used to crush stones and destroy tumor tissues with a strong mechanical power effect, diagnostic ultrasound is only using ultrasound as a signal, which requires very little power.

Therefore, diagnostic ultrasound has been considered very safe for many years. No significant side effects, including adverse effects on the embryo and early pregnancy fetus, have been detected under internationally defined safety threshold conditions.

Although ultrasound is a very safe imaging method, caution should be taken in routine diagnostic ultrasound work. This means using minimal power output, reducing the duration of the examination, avoiding prolonged exposure to fixed sites (especially the eye and early embryo), and minimizing the production of certain side effects that may be caused by ultrasound exposure.