Lipids play a variety of roles in living systems. They are a source of extremely high energy and a part of almost all signaling and biological processes. Despite the liver being the hub of lipid metabolism, lipid metabolism occurs across the human body. Any perturbation in the lipid metabolism or lipid storage systems can lead to diseases or disorders that can hamper the normal functioning of the human body. Lipids have been explored for their role in cancers. The intake of saturated fatty acids has been found to increase the metastasis and growth of cancerous cells. The role of lipids has also been studied in brain diseases. In Tay-Sachs disease, the inability to metabolize GM2 ganglioside alters normal nerve cell functioning. Similarly, lipids also play critical roles in Parkinson's and Alzheimer's disease. Moreover, atherosclerosis is a leading cause of cardiovascular diseases and brain stroke. Dyslipidemia or excess fatty acids is a leading cause of non-alcoholic fatty liver disease, insulin resistance, and diabetes mellitus. Dyslipidemia also leads to jaundice, which, in turn, can seriously damage the kidneys. This review focuses on the various human diseases occurring because of lipid metabolism.