Common variable immunodeficiency is an uncommon primary B-cell immunodeficiency condition characterised by multisystem problems due to weakened humoral immunity [1]. Is characterised by a paradoxical predisposition to a wide spectrum of autoimmune and neoplastic consequences, as well as inadequate adaptive responses to pathogen exposure. Primary immunodeficiency diseases are a diverse set of illnesses characterised by an increased vulnerability to recurring, severe infections. Invasive fungal infections have a high morbidity and mortality rate, which is a major concern. Various fungal infections among Primary immunodeficiency diseases patients are described in this paper. Infected patients with the human immunodeficiency virus have low CD4 lymphocyte counts and are vulnerable to a variety of bacterial, viral, and fungal diseases [2-3]. In addition to a wide spectrum of systemic manifestations, people infected with the human immunodeficiency virus have a number of distinct oral manifestations. Some oral symptoms have been linked to CD4 lymphocyte counts, which can be used as an independent prognostic predictor in studies. Several medications have been discovered and implemented to combat the human immunodeficiency virus. Patients with human immunodeficiency virus are given highly aggressive antiretroviral therapy, which includes a mix of antiretroviral regimens. According to studies, in addition to reducing viral activity, the treatment regimen has a substantial impact on the oral symptoms of patients infected with the human immunodeficiency virus. Infection, autoimmune diseases, and inflammatory disorders are all more common in people with Primary Immunodeficiency Disease. Although cognitive impairment, often known as brain fog, has been recorded in people with different medical problems and as a side effect of medications, it has never been described in people with Primary Immunodeficiency Disease.