About 20% of patients with kidney cancer feel well with no symptoms in the early stage, no matter how big the tumor is, and most of them find themselves with renal space-occupying lesions or a lump in the kidney area only when receiving physical examinations or B-mode ultrasonography. Some people with tiny primary tumors see no special signs in urinary or renal areas but feel discomforts caused by metastatic kidney cancer.
Why people with kidney cancer may have different symptoms? This is because the early signs and symptoms of kidney cancer include both non-urinary and renal ones.
Nearly 40% of patients with kidney cancer just shows some general symptoms including fatigue, poor energy, loss of appetite, dyspepsia, nausea and constipation. About 50% to 70% of patients experience fever, weight loss, liver dysfunction, gastrointestinal dysfunction, high blood pressure and low blood sugar. These non-urinary symptoms usually occur before urinary symptoms, for example, fever may happen about 2 to 6 months earlier than haematuria (blood in urine).
Kidney cancer has three main renal symptoms: hematuria, low back pain, and a lump or mass in the kidney area. If all three symptoms occur, the disease has almost developed into a late stage. Generally, only one or two happens at an earlier stage.
Blood in the urine
Blood in the urine (called hematuria) is the most common symptom of kidney cancer. About 50 out of 100 (50%) of people diagnosed with kidney cancer have it when they first go to the doctor.
Most blood in the urine can be seen by the naked eye without other accompanying symptoms including pain. It can come and go but occurs many times. When hematuria is found, you should go to the doctor immediately to avoid a late detection and diagnosis.
Low back pain
About 50% of patients will have low back pain when the tumor enlarges to strain the renal capsule or to pressure the peripheral nerves and muscle tissue. Usually, pains occur in the low back or upper abdomen, and occasionally, severe cramps occur when blood clots are discharged downward, which are easily misdiagnosed as kidney and ureteral stones.
A lump or mass in the kidney area
Renal lesions that are enlarged enough can be felt (or seen) from the waist or upper abdomen, and about 20% to 30% of patients have a lump or mass. The lump is easier to touch when taking the lateral position, and sometimes the lump can be seen moving up and down with the breath. If the lump is fixed and adheres to the surrounding tissue, the lesion develops at a late stage.
The initial warning signs of kidney cancer above mentioned are diverse, and most are general symptoms, and urinary symptoms appear only after cancer develops to a certain extent. Therefore, early detection and diagnosis of kidney cancer depend on people’s high vigilance against cancer. People over the age of 40 are advised to receive the urinary examination to rule out the possibility of kidney cancer when finding these symptoms.