
12 Ariz. App. 546 (1970)
473 P.2d 471
Lester D. LAWSON, Petitioner,
v.
The INDUSTRIAL COMMISSION of Arizona, Respondent, Wilson School District No. 7, Respondent Employer, State Compensation Fund, Respondent Carrier.
No. 1 CA-IC 428.
Court of Appeals of Arizona, Division 1, Department A.
August 18, 1970.
Rehearing Denied September 14, 1970.
Review Denied November 4, 1970.
Charles M. Wilmer, Phoenix, for petitioner.
Donald L. Cross, Chief Counsel, Phoenix, for Industrial Comm. of Ariz.
Robert K. Park, Chief Counsel, by R. Kent Klein, Phoenix, for respondent carrier.
CAMERON, Judge.
This case is before the Court to review the lawfulness of an award and findings of the Industrial Commission issued 13 February 1970 finding that the petitioner's claim was non-compensable.[1]
The facts necessary for a determination of this matter are as follows. On Friday, *547 16 August 1968, the petitioner, a 63-year-old school maintenance man, became quite confused and disturbed while at work. His problem was diagnosed as an acute brain syndrome associated with cerebral arteriosclerosis, and the particular symptoms were diagnosed as having been caused by blood insufficiency.
The petitioner contends that the stress and strain of his employment situation triggered the mechanism which caused the blood insufficiency.
Where the result of an accident for which workmen's compensation is claimed is of such nature that it is not clearly apparent to an ordinary layman, the physical condition of a workman can usually be ascertained only by expert medical testimony. Fyffe v. Industrial Commission, 10 Ariz. App. 377, 459 P.2d 104 (1969). The petitioner was supported in his theory by Dr. Samuel Wick, psychiatrist, who testified in his behalf. However, on cross-examination, Dr. Wick admitted that he could not be certain of the precise cause of the blood insufficiency and that in fact it could have happened spontaneously without any provocation of stress or strain. Dr. Abraham Ettleson, neurosurgeon, who examined and treated the petitioner, testified that he did not believe the petitioner's condition was in any way work-connected. Dr. William B. McGrath, psychiatrist, reviewed the file and testified that he found no causal relationship between the work and the incident. Awards of the Industrial Commission will be sustained if they are reasonably supported by the evidence, and an award based on conflicting medical testimony will not be disturbed on appeal. Burch v. Industrial Commission, 10 Ariz. App. 365, 459 P.2d 92 (1969).
It is the opinion of the Court that the award of the Industrial Commission is reasonably supported by the evidence.
Award affirmed.
DONOFRIO, P.J., and STEVENS, J., concur.
NOTES
[1]  This case was decided under the law as it existed prior to 1 January 1969.
