Continue writing the next sentence.

How to recognize male infertility 
Understand that male infertility often has no obvious signs. 
Many infertile men experience a regular sex life and have sperm that looks fine to the naked eye. In this sense, it is difficult to recognize the physical symptoms of male infertility.
Warning signs are rare, but some infertile men have lumps or swelling near the testicles, breast growth, erectile dysfunction, and respiratory problems. Feel for a lump or swelling in your testicles.