The immune system is body’s defensive mechanism that fights against infections. Immune system is made up of special cells, and organs that are present throughout the body. Lymphocytes also known as the White Blood Cells (WBC) are the key players in the immune system. The immune system restricts entry of infection-causing organisms such as bacteria, viruses, parasites, and fungi and thus prevents illnesses. However, when the Immunity is compromised the body loses capability of protecting you from infections. Immunity can be affected due to several reasons such as unhealthy lifestyle, stress, genetic disorders and ageing.