Brain fog with compromised ability to concentrate has been the most frequent Long Covid (LC) complaint. This is due to an increased transforming growth factor (TGF) β/interferon (IFN)-γ ratio with consequently increased bradykinin (BKN), especially in Caucasian females. Brain and lung blood vessels “leak.” This same ratio is increased in Alzheimer’s disease (AD), but decreased in Parkinson’s disease (PD), because CD4⁺ and CD8⁺ T cells are differentially affected by the invading associated viruses, e.g., SARS CoV2, HIV, Varicella Zoster (VZV) aka Human Herpesvirus 3 (HHV3), HBV, HCV, …. In Covid-19 CD147 receptors on immune cells are critical in generating the increased TGF-β/IFN-γ and those on endothelial cells, platelets, and erythrocytes are critical to the abnormal microvascular blood flow. ACE2 receptors on pneumocytes and enterocytes enable pulmonary and GI entry, initiating gut dysbiosis. Epigenetics, methylation, magnesium, vitamin D, the B vitamins, and antioxidants suggest that these issues can be surmounted. Biochemical, physiologic, and epidemiologic data are analyzed to answer these questions. An LC model is presented and discussed in the context of the most recent research. Suggestions to avoid these and other worrisome concerns are included. Other topics discussed include estrogen, the gut microbiome, type 2 diabetes (T2D), and homocysteine.