Dictionary of Space Concepts

The fluid shift in the body is an adaption to the reduced gravitation force in space. This results in a shift of the body fluids from the lower body to the upper body.

Detailed Definition:

When a human body is placed on the earth surface, it has a hydrostatic (gravitational) blood pressure gradient and every body region has a different arterial pressure.

In the reduced gravity of space, the hydrostatic pressure in the arteries and veins is altered to a homogeneous arterial pressure in all regions (which is the original arterial pressure of the hearth), which results in the shifted fluid distribution through the body.

The human body reduces the volume of the total fluid and after the space resident, the fluid is shifted because of the returned gravity force.

This phenomenon can cause several issues like cardiac arrhytmia, muscular athropy and visual problems (because the globe is flattened, the blood flow is changed slightly and the diamteter of the optical nerve can increase).

Etymology:
fluid - Latin fluidus ("fluid, flowing, moist")
shift - Proto-Germanic skiftan (" to divide, change, seperate")

Sample sentence(s):

A medical effect of a space flight may be a fluid shift.

Nasa is studying the effect of the fluid shift and how it affects changes in vision.

Translation:

French:

déplacement du fluide

German:

Flüssigkeitsverschiebung 

Polish:

Przemieszczenie płynów w ludzkim organizmie

Swedish:

vätskeförskjutning

Links to Videos/Articles:

https://www.nasa.gov/content/fluid-shifts-study-advances-journey-to-mars

https://ntrs.nasa.gov/citations/20150001888