Figure 3.

Graphical representation of the proposed relationship between health and stress, detectable using biochemical measurements but with no clinical manifestations, and chronic stress with related adverse clinical events. Stressful conditions, such as spaceflight or various deployment ground analogs of spaceflight, are represented on the continuum based on research findings. Note that current ISS astronauts general experience less stress due to certain deployed biomedical countermeasures (consequently less viral reactivation, improved cortisol levels, etc.), than astronauts during the ‘construction phase’ of ISS and therefore are represented lower on the stress continuum.