Most cases of kidney cancer don't cause any symptoms in the early stages. The most common symptoms of mid- to advanced-stage kidney cancer are: blood in your urine (haematuria) – the amount of blood is usually high enough to change the colour of your urine to a reddish or dark brown colour a persistent pain in your side, just below the ribs a lump or swelling in the area of your kidneys (on either side of the body) However, in around half of all cases, the cancer causes no symptoms and is only detected during a routine ultrasound scan. Less common symptoms of kidney cancer include: extreme tiredness (fatigue) or anaemia unintentional weight loss a high temperature of 38C (100.4F) or above night sweats a general sense of feeling unwell swelling of the veins in the testicles (in men) loss of appetite high blood pressure (hypertension