Hi,
Testicular shrinkage is usually due to
cold temperature, but it relaxes again, when exposed to a warm temperature.
Testicular atrophy is something which causes the testicle to become small, due to loss of some germ cells and Leydig cells. Some times, this atrophy is more, so that testicle cannot be felt manually.
Main cause may be aging, some infections,
hormonal imbalance or other medical conditions. In your case it may be age related and may be quite normal. However, if it is accompanied by other symptoms like pain, swelling,
fever,
weight loss or loss of appetite etc., then you are advised to see your doctor for precise diagnosis and treatment.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Satnarain Bansal, General & Family Physician