Kidney cancer rarely causes symptoms in the early stages. More than half of people with kidney cancer don’t notice any symptoms before their diagnosis. When symptoms do appear, they can be subtle and may be mistaken for other health problems. That’s why many people don’t realize something’s wrong until the disease is more advanced.

Although many people don’t experience any kidney cancer symptoms, there are some signs and symptoms to watch for. It’s also important to recognize symptoms that develop when kidney cancer spreads to other parts of the body. Continue reading to learn more about the most common symptoms from early to advanced stages of kidney cancer.

1. Flank Pain

Flank pain refers to pain on the sides of your lower back. Your flank region is the part of your body between your hips and ribs on your sides and lower back. Flank pain is often a sign of kidney problems, and it’s considered one of the classic symptoms of kidney cancer. However, only about 10 percent of people diagnosed with kidney cancer report feeling flank pain. When people do report kidney pain, they usually describe it as a constant dull ache.

Kidney cancer doesn’t often cause pain because it grows slowly. Kidney tumors that begin to grow deep within the kidney don’t push on surrounding organs until they grow larger. People may not feel pain until the kidney tumor grows large enough to reach the kidney capsule (the outer layer of tissue surrounding the kidneys), where there are more nerve endings.

Even in people who do experience flank pain, it’s difficult to know the cause. Several more common health conditions can cause flank pain, including:

• Urinary tract infections (UTIs)
• Kidney stones
• Arthritis
• Muscle spasms
• Pinched nerve in the spine
• Liver problems
• Shingles

2. Blood in the Urine

Hematuria (blood in the urine) is one of the most common symptoms of kidney cancer. About 40 percent of people diagnosed with kidney cancer have this symptom. Blood in the urine can happen in kidney cancer when the kidney tumor invades the collecting ducts — the tubes that collect urine in the kidney after it’s been filtered from the blood. This results in the rupture of the renal pelvis mucosa (the central part of the kidney).

Larger amounts of blood in the urine can discolor the urine and make it appear red, pink, or cola-colored. If you can see a color change in the urine, it’s known as gross hematuria. It’s important to know that the color change may not be there all the time — it may come and go. People with severe bleeding may also see blood clots, or small clumps of blood, in the urine.

If there’s a small amount of blood in the urine, the urine may appear normal. In this case, blood in the urine can only be detected with a urine test, or urinalysis. When it involves very small amounts that aren’t visible to the human eye, it’s known as microscopic hematuria. Blood in the urine is usually painless. If you have a small amount of blood in your urine, you may not notice any symptoms unless your healthcare provider checks for it.

Blood in the urine can be caused by many other health conditions, including:

• UTIs
• Kidney stones
• Enlarged prostate
• Endometriosis
• Injury to the kidneys or bladder
• Bladder or prostate cancer
• Kidney disease
• Sexually transmitted infections

3. A Lump on the Flank or the Abdomen

If a kidney tumor grows large enough, it may form a lump or mass that you can feel in your flank or abdomen. Most people diagnosed with kidney cancer don’t have a lump caused by a kidney tumor. That’s because when a kidney tumor is small, you won’t be able to feel it. As the tumor grows, it can be easier to detect a lump. A kidney tumor usually feels like a firm lump that doesn’t hurt when you press on it. If you have other symptoms, a healthcare provider may check for a kidney mass during a physical exam.

4. Anemia

Anemia is a health condition caused by low red blood cells (RBCs). When the red blood cell count is low, the blood can’t deliver enough oxygen around the body, causing weakness, tiredness, and shortness of breath. Anemia can be detected with a blood test.

Some people with advanced kidney cancer may develop anemia several months before their diagnosis. People with kidney cancer may develop anemia due to changes in a hormone made by the kidneys that tells the bone marrow to make more RBCs.

Even if anemia is found with a blood test, it may not point to kidney cancer. That’s because anemia can be caused by many other health conditions, including kidney disease, other types of cancer, and inflammatory bowel disease. It can also develop if you don’t get enough iron in your diet.

5. Unexplained Weight Loss

If you lose weight without meaning to, this is known as unexplained weight loss. Weight loss is a common symptom in many different types of cancer, including kidney cancer. People with kidney cancer may lose weight due to loss of appetite or a feeling of fullness from a large tumor. This symptom can also be a sign that cancer has spread to other parts of the body, a process known as metastasis.

Some people can experience weight loss during treatment. Kidney cancer treatments, such as immunotherapy, can cause weight loss and decreased appetite as a side effect.

6. Fever

People with advanced kidney cancer may develop a fever that doesn’t go away. The most common cause of fever is infection. However, people with advanced kidney cancer may have a fever that isn’t related to an infection. About 20 percent of people with kidney cancer develop fever.

Other symptoms that may come along with a fever in kidney cancer include:

• Increased sweating
• Night sweats
• Loss of appetite
• Tiredness
• Feeling generally unwell

7. High Blood Pressure

High blood pressure, or hypertension, may be a sign of kidney cancer. The kidneys make a hormone called renin that helps control blood pressure. If kidney cancer changes how well the kidneys work, it may also affect blood pressure. However, high blood pressure is also very common, affecting almost half of adults in the United States.

High blood pressure in kidney cancer is often part of a group of symptoms known as paraneoplastic syndrome. Other symptoms of paraneoplastic syndrome include hypercalcemia (high calcium levels in the blood) and polycythemia (abnormally high levels of RBCs). About 20 percent of people with kidney cancer have paraneoplastic syndrome when they’re diagnosed.

8. Swelling

Swelling in the lower legs or abdomen can develop if a kidney tumor blocks the inferior vena cava — the body’s largest vein. This vein carries blood to your heart from your lower body. If the inferior vena cava is blocked by a kidney tumor, it can cause the blood to back up in the lower half of the body.

9. Enlarged Veins in the Scrotum

According to Wolters Kluwer UpToDate, up to 11 percent of males with kidney cancer have an enlarged vein in their scrotum, usually on the left side. An enlarged vein on the scrotum is also known as a scrotal varicocele.

An enlarged vein on the scrotum can happen if a kidney tumor blocks the vein that carries blood away from the testicles. The enlarged veins may look like a bag of worms or an area of swelling on the scrotum.

It’s important to note that scrotal varicoceles usually aren’t a sign of kidney cancer. According to Cleveland Clinic, as many as 1 in 5 men in the United States have this condition. However, this condition should always be checked by a healthcare provider.

Symptoms When Kidney Cancer Spreads to Other Parts of the Body

You may have additional symptoms if the kidney cancer metastasizes (spreads to another part of the body). The exact symptoms depend on where the cancer has spread. Common symptoms depend on the location of the metastasis. A few examples include:

• Adrenal glands — Back pain and digestive problems
• Lungs — Shortness of breath and cough
• Bones — Bone pain or bone fractures
• Liver — Jaundice (yellowing of the skin and eyes) and abdominal swelling
• Brain — Headaches or seizures

It’s important to talk to your cancer care team about all of the symptoms you experience. Even if you already have a kidney cancer diagnosis, new or worsening symptoms can help guide additional testing and treatment options.

Find Your Team

On MyKidneyCancerTeam, the social network for people living with kidney cancer and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with kidney cancer.

What signs and symptoms of kidney cancer did you have when you were first diagnosed? Share your experience in the comments below, or start a conversation by posting on your Activities page.