Cancer, including kidney cancer, raises the risk of blood clots. Some blood clots can be life-threatening. In general, blood clots are the second leading cause of death for people with cancer. Between 10 percent and 20 percent of people with cancer develop a blood clot at some point.

Learning to recognize the symptoms of a blood clot can help you identify it before it causes a dangerous blockage.

Keep reading to learn about the risk factors for blood clots with kidney cancer and what symptoms to watch for.

What Types of Blood Clots Can Happen With Kidney Cancer?

Certain blood clots are more common in people with kidney cancer. Here are two types you should be aware of.

Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a blood clot that develops in the arms or legs. Catching a DVT early, while it’s still in the limbs, can help you get lifesaving treatment. If left untreated, a DVT may break loose in the blood vessel and move into the lungs. This dangerous complication is called a pulmonary embolism, and it requires emergency medical treatment.

Renal Vein Thrombosis

It’s also possible to develop a blood clot in the renal vein. Anything that puts pressure on this area increases the risk, including tumors on the kidney.

Renal vein thrombosis usually develops gradually. You may not notice any symptoms. However, it still poses a serious risk of pulmonary embolism if any part of the clot becomes dislodged and enters the bloodstream.

What Are the Risk Factors for Blood Clots?

People with kidney cancer have a higher risk of blood clots. Some risk factors are the same for many types of cancer. Others are uniquely related to kidney tumors or treatment side effects of kidney cancer drugs.

Lack of Physical Activity

Having any type of cancer can make it harder to live an active lifestyle. Cancer can cause fatigue and reduce your motivation to exercise. Unfortunately, lack of movement is a major risk factor for blood clots.

Pressure on the Veins of the Kidney

In addition, a mass on the kidney raises pressure on the renal vein. This directly affects the risk of renal vein thrombosis.

Kidney Cancer Treatments

In general, being hospitalized and having surgery can raise your risk of blood clots. This is especially true if you need a catheter after surgery. The risk of blood clots is also higher if your cancer treatment requires intravenous medications (as with chemotherapy).

Certain targeted drugs and immunotherapies used for kidney cancer are associated with blood clots. Bevacizumab (Avastin) is a targeted therapy that may be prescribed for people with metastatic renal cell carcinoma (advanced kidney cancer). Higher risk of blood clots is a possible side effect.

There’s also a higher risk of dangerous embolisms when people with the most common type of kidney cancer, renal cell carcinoma (RCC), are treated with immunotherapy.

Your healthcare provider will consider your overall medical history and current risk factors before recommending the cancer treatment options for you. Together, you’ll make decisions based on which treatments have more potential benefits than risks for you.

If clotting is a concern, they may monitor you more closely or prescribe preventive medications to help reduce this risk.

Other Risk Factors

The risk of blood clots can run in families. Pay careful attention if you inherited a clotting disorder or have close relatives with a history of blood clots. Other risk factors include:

• Diabetes
• Hypertension (high blood pressure)
• Serious injuries and hospitalizations
• Lung disease
• Obesity
• Oral contraceptives (birth control pills)
• Smoking

Symptoms of Blood Clots

If you have any potential symptoms of blood clots, talk to your doctor right away. They can run blood tests and order an ultrasound or a computed tomography (CT) scan to check for clots and provide treatment.

1. Pain

Blood clots can cause pain or tenderness at the site of the clot. If you have pain in a specific area and don’t remember getting injured, a blood clot could be the cause.

In renal vein thrombosis, pain is usually the first symptom. It may build over time, affecting the lower back and hips.

2. Swelling

One of the telltale signs of a DVT is a swollen hand, leg, foot, or ankle. Clots cause blood to pool, which leads to fluid buildup that expands the affected area.

This is different from generalized swelling or edema. Instead of affecting both sides of the body, swelling from a clot is only on the limb where the clot is located.

3. Skin Discoloration

In addition to swelling, the skin surrounding a blood clot may look red or discolored. Skin color changes may be harder to spot on people with darker skin.

4. Warmth/Fever

Skin that’s swollen and inflamed from a blood clot may feel warm to the touch. In addition, renal vein thrombosis may cause fevers as a symptom. If you have a hot area on your body or a general fever, bring it to the attention of your oncology team.

5. Urine Changes

People with renal vein thrombosis may notice that they’re peeing less often or there’s blood in the urine.

The symptoms of renal vein thrombosis often overlap with common symptoms of kidney cancer, kidney disease, and kidney infections. Paying attention to any new or worsening symptoms can help you tell if there’s something else happening to your kidneys.

6. Nausea and Vomiting

Blood clots can also affect the digestive system, making you feel sick to your stomach. Renal vein thrombosis and other clots in the abdomen, liver, or spleen may cause nausea and vomiting.

7. Stroke

Blood clots that block blood flow to the brain can cause a stroke. Stroke symptoms may include blurry vision, drooping on one side of the face, slurred speech, and intense headaches or dizziness.

8. Pulmonary Embolism

A pulmonary embolism can alter your heartbeat and ability to breathe normally. You may notice shortness of breath, coughing up blood, and chest pain that gets worse with breathing.

A pulmonary embolism is a medical emergency. Studies suggest that people with RCC have a higher risk of embolisms than both the general population and those with other types of cancer.

Seek help right away if you suspect that you or a loved one is experiencing a pulmonary embolism.

How Can You Lower Your Risk?

Let your healthcare provider know about any risk factors you have for blood clots. Aside from kidney cancer, talk to them about your family history, other medical conditions, and your lifestyle — especially your exercise habits and any injuries.

Medication

Blood thinners, including antiplatelet drugs and anticoagulants, can help prevent clots. Some people need to take these medications long term. Doctors may also prescribe them temporarily for high-risk situations, like long travel or after surgery.

Lifestyle

Lifestyle changes, like stretching and moving your body every couple of hours, drinking plenty of water, and not smoking, can also help prevent blood clots. Your doctor may also encourage you to wear compression socks to reduce your blood clot risk.

If you develop a blood clot, there are effective ways to test for and treat it. The key is finding it in the early stages to keep it from growing larger or doing serious damage.

Join the Conversation

On MyKidneyCancerTeam, people share their experiences with kidney cancer, get advice, and find support from others who understand.

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