What’s behind the signs and symptoms of kidney cancer

The symptoms of kidney cancer appear in places like your urine or lower back. Most symptoms have to do with your kidney function and tumor growth.

The kidneys are two bean-shaped, fist-sized organs under the backside of your rib cage. They help:

  • filter waste from your blood
  • create urine
  • control blood pressure
  • create red blood cells

Your body can function normally with only one kidney. But when there’s a tumor growing, your kidney’s normal functions may be disrupted.

Kidney cancer, also called renal cell carcinoma (RCC) is one of the 10 most common cancers in both men and women. But symptoms don’t often appear until later stages, or until the tumor is large. Kidney cancer is most commonly diagnosed in people over 60 years old. It’s often found by accident during routine imaging tests.

Hematuria, or blood in the urine, is one of the most common symptoms. It appears in 40 to 50 percent of people with kidney cancer, according to the Kidney Cancer Association.

Even a small amount of blood can cause a color change such as pink, brownish, or even red. The presence of blood can be inconsistent, appearing about every other day. Sometimes the amount of blood is so small it can only be detected during a urinalysis.

Other more common causes of blood in the urine include bladder or kidney infection, kidney stones, cysts, or injury to the kidney. Always see a doctor if you detect blood in your urine.

Back pain is common in people over 40 years old. This is usually due to musculoskeletal injury or disk degeneration. Back pain is also less commonly a symptom of kidney cancer. About 41 percent of people with RCC report back pain. But most people don’t experience back pain until the cancer is in the later stages.

The pain can range from a dull ache to a sharp stab on one side of your flank or below the ribs on your back. Your flank is the area between your lower back and the bottom of the backside of your ribs. It may also feel like side pain to some people.

The type of pain associated with RCC can vary. Some people report pressure instead of an ache or sharp pain. See a doctor if you have any sudden pain that is persistent and lasts more than a few days. Mention any other symptoms during your visit to help your doctor determine the likely cause.

A mass or lump in the abdomen, side, or back can also be a sign of kidney cancer. It can feel like a hard, thickening, or bulging bump under the skin. About 45 percent of people with RCC have an abdominal mass.

But kidney lumps are hard to feel, especially in the early stages. That’s because the kidneys sit deep in the abdomen. You may not even see or feel the lump as the tumor grows.

If a lump is discovered, your doctor will likely order diagnostic tests. Usually an ultrasound or a CT scan. These tests may help determine the cause of the lump. In most cases a biopsy will be needed to confirm the diagnosis.

Keep in mind that not all lumps are cancer. Talk to your doctor if you’re concerned about a lump around your abdomen.

Fatigue is one of the most common symptoms of any type of cancer, especially during treatments. About 70 to 100 percent of people who undergo cancer treatments report fatigue. Many people with cancer say fatigue is one of the most difficult symptoms to manage.

Fatigue from cancer is different than just feeling tired from lack of sleep. Cancer-related fatigue is persistent and interferes with daily activities. It can also intensify as time goes on.

About 21 percent of people with kidney cancer have anemia, or low red blood cell count. Normally your kidneys signal your body to make red blood cells. Cancer can interfere with that signaling. Anemia can also cause worsening fatigue, shortness of breath, dizziness, and pale looking skin.

Make an appointment with your doctor if you’re feeling unusually tired. They can run tests to help diagnose the cause and find the right treatment.

About 28 percent of people with kidney cancer report weight loss. This usually happens quickly, as the tumor spreads to other organs. You may suddenly lose interest in eating, even when you’re not trying to lose weight. This loss of appetite can contribute to weight loss.

A fever on its own isn’t usually a symptom of kidney cancer, but unexplained and recurring fevers may be. These fevers are usually not caused by an infection and commonly will come and go.

Some individuals are more likely to develop kidney cancer than others. Risk factors include:

  • age (as you get older, your chance of kidney cancer increases)
  • smoking
  • obesity
  • high blood pressure
  • treatment for kidney failure
  • certain genetic or hereditary factors
  • male gender

Certain steps can be taken to prevent or lower your risk for kidney cancer. For example, you can manage high blood pressure with lifestyle changes and medication.

Maintain a healthy weight and diet, and don’t smoke. Avoid frequent exposure to harmful carcinogenic substances can also decrease your chances of developing kidney cancer.

Tell your physician if you have a personal or family history that includes cancer. This can help determine your risk factors for developing RCC.

If you have any symptoms of kidney cancer, your doctor will order tests to help determine the cause. Possible tests include a urinalysis, and culture and blood tests to check for anemia. Your liver and kidney function, and other metabolic functions will also be analyzed.

If your doctor finds a lump, they may use imaging tests, such as ultrasound, CT scan, or MRI. If a lump or a mass is found on your imaging tests, you will likely need a biopsy to determine whether or not you have cancer.

It’s important to know the signs and symptoms of RCC, especially if you have a family history or other risk factors. Most of the symptoms of kidney cancer can be the result of other less serious problems. But these symptoms should not be ignored, especially if you have more than one of them.

Make an appointment with your doctor if you have any of these symptoms.

Kidney cancer often shows no signs until later stages, so it’s important to see a doctor as soon as symptoms arise. With an early diagnosis, you can increase your chance of successful treatment and improve the long-term outlook of your condition.