Sperm count in your ejaculate can vary throughout your life. A healthy sperm amount is often necessary for fertility. The World Health Organization (WHO) classifies sperm counts at or above 15 million sperm per milliliter (mL) of semen as average. Anything below that is considered low and is diagnosed as oligospermia. 

   Since these sperm deformities do not  tend to have any effect on sexual function, men may not know they have this unless they are having trouble conceiving with a partner. Though Many men with oligospermia are able to father a child.

Causes of the Male infertility : 

• Alcohol ,  Smoking and  drugs

• For example, Anabolic steroids, cocaine, marijuana etc.  

• Emotional stress : it interfere  with certain  hormones 

• Lifestyle  disorders : Obesity, Diabetes etc. 

• Electromagnetic radiation Such like laptop, computers, cell phone, x-rays etc. 

• Malnutrition : Deficiencies in nutrients such as vitamin c, selenium, zinc

• Tobacco smoking

Ayurvedic causes for male infertility

• Bija upa tapa (Congenital abnormalities)

• Sukra dosha (Diseases of sperm)

• Aghat : Any physical trauma to testicles 

• Ahit Ahahr : excessive use of dry, bitter, astringent, salty, acidic  and  hot  food.  Foods  which are  at variance  with place,  time,  power of  digestion,  quantity,  habit,  doshas

• Ahit Vihar : bodily exertion in excess, suppression of natural urges.  Also  behavioral habits  like  sleeping  very  late at  night,  hectic  lifestyle 

• Dhatu Paak : autoimmune disorders 

• Anashan : Malnutrition 

• Manopaghat : Psychological factors : ecess stress , mental trauma , Excessive sexual  indulgence, , sexual abuse, absolute sexual abstinence, leads  to disparity  of  Rakta and  Pitta  Dosha,  ultimately causing Shukra kshaya.