Infertility is usually defined as a pair not being able to have a baby after a year of having sexual relations often and without protection. It impacts around one-fifth of American couples and at least one-hundred million people globally. As Infertility is mostly caused by female variables, which include various issues with ovulation, oocyte maturation, fertilisation competence, and the ability of a fertilised egg to undergo preimplantation development, implantation, and foetal growth. These factors account for at least 35% of all infertility cases. Additionally, male factors are thought to be responsible with 20–70% of occurrences, varying by latitude. A decrease in semen quality, showing as decreased sperm counts (or even the total deficiency of sperm in ejaculate), and abnormal sperm quality and function due to impaired spermatogenesis in the gonads and/or dysfunction of the adjunct glands, are symptoms of infertility of male, which can have a number of well-defined inherited or acquired causes. Consequently, this article provides comprehensive reviews of this important men's and women's health problem, how to evaluate infertility, the significance of using these methods, and basic and clinical studies investigating novel approaches to diagnostic tools, treatment options directed towards personalised medicine, and preventive strategies in male and female infertility.