A kidney tumor is a mass of abnormal cells that forms within the tissues of the kidney 2. Your kidneys are located on either side of your body. Kidney tumors can be cancerous or noncancerous 2. Small kidney tumors may not cause any symptoms initially 2. Growing noncancerous tumors and cancerous kidney tumors, however, eventually lead to symptoms that should be discussed with a doctor 2.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Blood in the Urine

If you have a kidney tumor, small amounts of blood are likely to be excreted in your urine. Blood in the urine -- a symptom called hematuria -- can cause your urine to appear brown or the color of rust. If you notice blood in your urine, contact your doctor as soon as possible. This symptom is common in people with kidney cancer, but blood in the urine can also indicate a different medical issue, such as infection 2.

Back or Side Pain

If you have a kidney tumor, you may experience mild to severe pain in your back, immediately above the site of the affected kidney, or in your side 2. The pain is likely to be constant, making it uncomfortable for you to move about normally. You may feel achy or pains may be sharp. Back and side pain can spread to your abdominal region. If this occurs, it may lead to additional symptoms such as nausea or stomach upset. People with kidney cancer are also likely to experience constipation.

Lump or Mass

The tumor in the kidney can eventually grow large enough to feel as a lump 2. Your doctor may be able to feel a raised bump when she presses your side or lower back. A kidney mass or lump can be tender to the touch and is likely increase further in size as the tumor grows 2.

Fatigue or Weight Loss

A kidney tumor may cause you to be tired. You may find that you do not have the energy to participate in your usual activities or that you require frequent naps throughout the day to remain active. Unintended weight loss is another symptom of a cancerous kidney tumor. You may find that symptoms of low back pain and nausea negatively affect your normal appetite, leading to decreased food consumption. Some people with kidney tumors also experience persistent fever in conjunction with these symptoms, which can lead to a general feeling of illness 2.

Other Changes

A woman with a kidney tumor may notice excessive hair growth, called hirsutism, on the face and body 2. A man may experience swelling in the veins of one of the testicles. Skin may take on a pale tone, called pallor. Decreased quality of visual perception in both men and women with kidney tumors has been described 2.