A primary immunodeficiency (PI) diagnosis places patients among a group of illnesses brought on by immune system genetic flaws. Since there is no treatment for PI, early diagnosis and a strategy to manage symptoms are essential for general health. But more recently, a deeper comprehension of the underlying PI mechanisms has resulted in novel approaches to boosting the immune system as well as more efficient treatments for various ailments. Primary immunodeficiency has made significant strides in the 21st century. Among those are improvements in targeted medicines, next-generation sequencing, and advancements in diagnostic tools such as the introduction of new-born screening for severe combined immunodeficiency. It is crucial to test all babies for severe combined immunodeficiency (SCID) in order to identify infants before they contract infections. Many individuals with PI may benefit from more individualised therapy choices thanks to next-generation sequencing (NGS). The researchers emphasise that future advancements in sequencing techniques and data interpretation will further advance the identification and care of patients with primary immunodeficiency. Additionally, there have been significant advancements in the treatment of patients receiving hematopoietic stem cell transplants from different donors, including the use of tissue type and antibiotic and antifungal therapy. Intravenous immunoglobulin therapy replaces antibodies that the immune system may lack in PI patients and raises platelet count, which may aid in the prevention and control of bleeding in some cases. These drugs, which contain proteins that fight infections and are derived from healthy human plasma, are infused into patients with PI. These medications are administered over a three- to four-week period on consecutive days. Although they do have side effects (no medicine is without them), they can significantly enhance PI patients' quality of life in ways that were not feasible ten years ago.