We may not hear a lot about kidney cancer but it is the twelfth most common cancer in the world. (1) Kidney cancer symptoms aren’t always straightforward, especially in the begining stages. This can make it difficult to diagnose. Kidney cancer includes cancer of the whole organ itself (renal cell carcinoma) and renal pelvis cancer, a rarer form that occurs in the center part of the kidney (the renal pelvis). Approximately 340,000 new cases of kidney cancer occur each year worldwide. The overall incidence of new cases of kidney cancer, however, has plateaued over the last several years. (2)
Research has found the following primary causes of kidney cancer:
- Cigarette smoking
- Medications containing phenacitin and cyclophosphamide (3, 4, 5)
- Obesity – the World Cancer Research Fund International states:“…about 24% of kidney cancer cases could be prevented in the USA if everyone had a healthy weight. The estimate was about 19% for the UK, 13% for Brazil and 8% for China.” (6)
- Polycystic kidney disease
- Lifestyle – diet, lack of regular physical activity, occupational exposure to toxins (7):“RCC [renal cell cancer] may also be due, in part, to unhealthy lifestyle factors that have been on the increase over the past several decades,” write a 2001 study. (8)
How Your Kidneys Work
We have two kidneys, located just below the rib cage on either side of the spine. Each are about the size of a fist.
Their function is to filter waste and toxins out of the blood, turning them into urine. The urine then travels through the ureters to the bladder, which holds urine until passed out of the body through the urethra.
Every day, the kidneys filter 120-150 quarts of blood and another 50 quarts of other fluids. (9) Kidneys also regulate the amount of salt, potassium, and acids in the body. They also secrete hormones that regulate blood pressure and the metabolism of calcium, metabolize vitamin D from other body chemicals, and promote the creation of red blood cells. (10)
Each kidney contains approximately one million tiny filters called nephrons that contain even smaller filters that allow small liquid molecules to pass through but block larger molecules (such as blood cells and proteins) to return to the bloodstream. The liquids then pass through tubes that further filter the liquid, returning nutrients to the blood and sending waste down the line for processing as urine. (11)
Without your kidneys (you need one fully-functioning kidney to survive), your body cannot eliminate waste and it becomes septic.
11 Kidney Cancer Symptoms
Kidney cancer often goes undiagnosed because the signs of kidney cancer often don’t manifest until later stages. It’s common for a tumor to be found when examining for other illness or when certain seemingly separate conditions exist. (12) It’s important, therefore, to know the subtle kidney cancer symptoms so that if it occurs, it can be caught early and treated.
1. Blood in Your Urine
Because the kidneys filter blood and other bodily fluids, forming urine from the waste, blood in the urine (hematuria) is one of the most obvious kidney cancer symptoms. However, other conditions can also result in blood in the urine, such as kidney stones or a urinary tract infection. (13) In fact, blood in the urine is most often caused by something other than kidney cancer. (
In fact, blood in the urine is most often caused by something other than kidney cancer. (14) If your urine is regularly red, pink, or brownish over the course of a week or two, however, it’s wise to see your healthcare provider to check it out.