Anti-VEGF therapy, which targets vascular endothelial growth factor (VEGF), is used in cancer treatment to inhibit angiogenesis. However, it can cause adverse effects due to the suppression of VEGF signaling in normal organs, leading to vascular disturbances and regression of blood vessels. These effects are generally manageable and less severe than the tumors being treated, but they highlight similarities between tumor vessels and normal vasculature. Three anti-VEGF drugs—bevacizumab, sunitinib, and sorafenib—are approved for cancer treatment. Bevacizumab, a monoclonal antibody, is used in combination with chemotherapy for colorectal and lung cancers. It can cause hypertension, proteinuria, and other side effects. Sunitinib, an oral inhibitor, is used for renal cell carcinoma and gastrointestinal stromal tumors. It causes fatigue, diarrhea, and skin reactions. Sorafenib, another oral inhibitor, is used for renal cell carcinoma and hepatocellular carcinoma, and causes rash, diarrhea, and fatigue. Preclinical studies show that VEGF inhibition can cause regression of capillaries in normal organs, such as the thyroid and pancreas, and may lead to endothelial dysfunction. These effects are reversible in some cases. Hypertension is a common side effect, often managed with antihypertensive drugs. Proteinuria is also common, reflecting the role of VEGF in renal function. Impaired wound healing is another effect, with delayed healing and complications in some patients. Gastrointestinal perforation, hemorrhage, and thrombosis are rare but serious side effects. These can be caused by VEGF inhibition leading to vascular changes. Reversible posterior leukoencephalopathy syndrome is a neurological condition associated with VEGF inhibitors, characterized by brain edema and other symptoms. Cardiac impairment, including reduced cardiac output, has been observed in some patients. Endocrine dysfunction, such as hypothyroidism, can occur due to capillary regression around the thyroid. These adverse effects are generally manageable but highlight the complex role of VEGF in normal physiology. As VEGF inhibitors are used more widely, understanding their mechanisms and managing their side effects becomes increasingly important.Anti-VEGF therapy, which targets vascular endothelial growth factor (VEGF), is used in cancer treatment to inhibit angiogenesis. However, it can cause adverse effects due to the suppression of VEGF signaling in normal organs, leading to vascular disturbances and regression of blood vessels. These effects are generally manageable and less severe than the tumors being treated, but they highlight similarities between tumor vessels and normal vasculature. Three anti-VEGF drugs—bevacizumab, sunitinib, and sorafenib—are approved for cancer treatment. Bevacizumab, a monoclonal antibody, is used in combination with chemotherapy for colorectal and lung cancers. It can cause hypertension, proteinuria, and other side effects. Sunitinib, an oral inhibitor, is used for renal cell carcinoma and gastrointestinal stromal tumors. It causes fatigue, diarrhea, and skin reactions. Sorafenib, another oral inhibitor, is used for renal cell carcinoma and hepatocellular carcinoma, and causes rash, diarrhea, and fatigue. Preclinical studies show that VEGF inhibition can cause regression of capillaries in normal organs, such as the thyroid and pancreas, and may lead to endothelial dysfunction. These effects are reversible in some cases. Hypertension is a common side effect, often managed with antihypertensive drugs. Proteinuria is also common, reflecting the role of VEGF in renal function. Impaired wound healing is another effect, with delayed healing and complications in some patients. Gastrointestinal perforation, hemorrhage, and thrombosis are rare but serious side effects. These can be caused by VEGF inhibition leading to vascular changes. Reversible posterior leukoencephalopathy syndrome is a neurological condition associated with VEGF inhibitors, characterized by brain edema and other symptoms. Cardiac impairment, including reduced cardiac output, has been observed in some patients. Endocrine dysfunction, such as hypothyroidism, can occur due to capillary regression around the thyroid. These adverse effects are generally manageable but highlight the complex role of VEGF in normal physiology. As VEGF inhibitors are used more widely, understanding their mechanisms and managing their side effects becomes increasingly important.