PROBLEM TO BE SOLVED: To provide an observation method capable of discriminating presence/absence of the subpapillary vascular plexus in a capillary vessel image captured by magnifying the capillary vessel of a cuticle of a fingertip and determining turbidity of a body fluid in the capillary vessel image.SOLUTION: An observation method of a capillary vessel image captured by magnifying the capillary vessel of a cuticle of a fingertip, includes discriminating presence/absence of the subpapillary vascular plexus running in a traverse direction traversing the longitudinal direction (a vertical direction) of a finger in the capillary vessel image. Besides the presence/absence of the subpapillary vascular plexus, it is preferable to determine turbidity of the body fluid in the capillary vessel image. Further, it is preferable to further determine a bending degree of a tip part of a blood vessel running in the longitudinal direction of the finger in the capillary vessel image.SELECTED DRAWING: Figure 8
