What are the testicles' conditions that prevent you from joining the military?

Multiple: Absence of testes, absence of one testes, (undescended testes) abnormal size or shape. Abnormal massess. Presence of hernia is what the examiner is most interested in seeing.

An absent testicle: Undescended testicle, testis tumor, large varicocele or scrotal hernia are all conditions which coulod prevent u from joining military. However an undescended testicle can be brought down surgically, hydrocele or hernia could be repaired. These are 3 correctable conditions, which after correction would make u ok to join.