Difficult to say without examination. Two things come to mind. This can include the hormone possibilities that you alluded to. A decrease in testosterone levels can
leadLead poisoning to
testicularTesticular biopsy
Testicular cancer
Testicular torsion
Testicular torsion repair
Testicular torsion repair - series reduction. A simple blood test can check for this.
You can also consider evaluating the
vascularArteriosclerosis of the extremities
Birthmarks - red
Dementia
Heart disease
Intravascular ultrasound
Mesenteric artery ischemia
Renovascular hypertension
Replantation of digits
Stroke
Tobacco and vascular disease
Vascular headaches supply to the testes - which can also reduce size. An ultrasound would be the appropriate test to evaluate for this.
These options can be discussed with your personal physician or urologist.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com