What is kidney cancer? Most kidney tumors are malignant, which means that a malignant mass grows on the kidney. There are many kinds of kidney cancer, but most of them are renal cell carcinomas, which originate from the urinary tubular epithelial system of the renal parenchyma and are divided into different subtypes according to the different sites of origin in the urinary tubules. The etiology of kidney cancer is unknown, and its development is associated with heredity, smoking, obesity, hypertension and anti-hypertensive treatment. Hereditary kidney cancer or familial kidney cancer accounts for 2-4% of kidney cancer. How to detect kidney cancer? What are the manifestations of kidney cancer? Early stage kidney cancer has no clinical symptoms and patients may not feel anything, most of them are found by physical examination. With the development of tumor, some symptoms will appear when the tumor presses and invades the surrounding tissues. The main clinical symptoms of kidney cancer are hematuria, pain and lumps, which are often referred to as the “triad signs” of kidney cancer by doctors. However, only a few patients have these three symptoms, and many patients may have only one of them, and they are often not specific enough to attract attention. Sometimes, patients with advanced kidney cancer may experience weakness, weight loss, loss of appetite, increase in blood red blood cells, increase in blood calcium, increase in blood pressure, sometimes the body may experience hot flashes or red skin, gynecomastia, etc. without any obvious reason. Some patients may present with lesions in the armpits, lungs, and other organs, which are found to be metastases only after puncture biopsy or surgery. None of these symptoms are specific and not every patient will present.