The worst and more obvious factors that are included in the list of men infertility causes are the foreign or unhealthy vices that men undertake, more known as toxic substances which include high exposures to metal, drugs, radiation and heavy smoking. All of these have been known to be unhealthy for the human body but still, people are inhaling and taking in all these substances without knowing and understanding the extent of its danger. To some this will be a cause for debate, but ideally, these things have never been able to help the human body or get any reasonable benefit from them.