Spotting blood in your urine can be a jarring and frightening experience. But it can also be unsettling to learn that you have occult – or hidden – blood in your urine. This invisible bleeding can only be detected by a microscope or urine blood test strips. As a result, you may not be aware that the chemical composition of your urine falls outside the normal range.
The presence of blood in urine may indicate either harmless or worrisome health conditions, depending on the underlying physiological factors.
Many people immediately assume that the presence of visible or occult blood in their urine is a sign of cancer. While hematuria (blood in urine) is associated with certain cancers, bleeding can indicate other health conditions (such as infections, kidney/bladder stones, ulcers, injury, high-intensity sports activity, etc.). Monitoring your urine for blood can help you notice these problems and seek appropriate medical treatment.
Can blood in urine be a sign of cancer?
Approximately 20% of people with visible hematuria – or blood in urine – and 5% with nonvisible have genitourinary cancers [1] (relating to genital and urinary organs). Here are three types of cancers that can cause blood in urine and other signs you may notice.
Bladder Cancer
Bladder cancer is the sixth most prevalent cancer in the United States and makes up approximately 5% of all cases. This condition typically occurs when a malignant tumor grows in the urothelial tissue lining the bladder tract. Non-urothelial cancer can also develop in other parts of the urinary tract system, such as the renal pelvis [2].
Blood in urine is the most common sign of bladder cancer. This fluid may be macroscopic – visible to the human eye – or occult. Between 0.4% and 6.5% of people with asymptomatic occult hematuria have bladder cancer. Patients with macroscopic bleeding are 20% more likely to have malignancy than those with occult bleeding [2].
Other symptoms of bladder cancer include [3]:
- Very frequent urination
- Needing to urinate urgently
- Pain or burning while urinating
- Unexplained weight loss
- Pain in the back, abdomen, or bones
- Fatigue
- Feeling unwell
However, these symptoms can also be caused by more common disorders, such as an infection or an enlarged prostate gland [3].
Around 90% of people diagnosed with bladder cancer are older than 55 years. Men are three to four times more likely to get diagnosed with this condition than women [2].
Kidney (Renal) Cancer
Kidney cancer is the eighth most prevalent cancer in America. It occurs when tumors grow in your kidneys. Unlike bladder cancer, kidney cancer is often asymptomatic. Many people discover this condition when they have an abdominal scan for another disorder [4].
For people who do experience symptoms, blood in the urine is the most common sign of kidney cancer. You might see macroscopic blood that comes and goes in the urine, or the blood might be microscopic. Other symptoms of kidney cancer include [5]:
- A lump or mass near the kidneys
- Pain in your side between your ribcage and hip
- Weight loss
- Fever
- Profuse sweating
- Fatigue
- Loss of appetite
Prostate Cancer
Prostate cancer is the second most prevalent cancer in American men. Around 1 in 8 men will get diagnosed with this condition during their lifetime, and 60% of men who develop prostate cancer are 65 or older [6].
Blood in urine can indicate male prostate cancer. You may also notice these symptoms [7]:
- Frequent urination, especially at night
- Slow or weak urine stream
- Erectile dysfunction
- Pain in the hips, spine, or ribs
- Weakness or numbness in the lower limbs
- Loss of bladder or bowel control
