Red Urine Has Many Causes: Some Life Threatening, Some Harmless

Red urine sometimes means blood in the urine, but sometimes it doesn’t.

Either way, you need to find out the cause of red or rust colored urine.

Some causes of red/blood in the urine are serious, including cancer; while some causes are quite benign (harmless).

These include repeated jarring from exercise. This happened to me some years ago when I was pedaling super furiously on a stationary bike, jostling it around: equipment I normally didn’t use.

A visit to the restroom right after revealed blood stains on my panties, but no blood or red in the urine, nor any red staining after that visit.

“Any trauma, regardless of how seemingly trivial, may cause bleeding within the urinary tract,” says Andrew Stephenson, MD, Section Chief and Director, Urology Oncology; Professor (PAR), Department of Surgery, Division of Urology, Rush Medical College.

“Gross (visible) blood in the urine after trauma is a reason to seek medical attention.”

What do these symptoms really mean?

Dr. Stephenson explains, “Microscopic blood cells in the urine is very common and may not be associated with any disease process within the urinary tract — about 5-10 percent of patients with microscopic hematuria (blood in urine) will have an identifiable cause (e.g., kidney stone, bladder cancer, etc.).

“Gross [visible] blood in the urine is usually associated with urinary tract pathology (e.g., kidney, bladder or prostate disease) or stones or infection.

Visible blood in urine can cause a tea or cola color, as well as an orange-red color. Credit: James Heilman, MD/CreativeCommons

What percentage of people who have kidney/bladder/prostate cancer, have this symptom?

“Blood in the urine from prostate cancer is uncommon in the absence of advanced disease,” says Dr. Stephenson.

“Most patients with bladder or kidney cancer will have microscopic blood cells present in the urine.”

Is this a very rare, or very common (or some range in between) symptom of kidney/bladder/prostate cancer?

“Three to five red blood cells per high-powered field on microscopic examination of the urine on more than one occasion is an indication for further investigations.”

How often or what percentage of diabetics have the symptom?

“Very uncommon in the absence of infection.”

Is this a common symptom of kidney stones?

“Yes. Also, abdominal pain or flank pain will be present if the stone has passed from the kidney into the ureter.”

More Additional Causes

Red Color but no Blood

Porphyria — a skin and nervous system disease

Beets, blackberries, rhubarb pie

Ex-lax and other laxatives

Some prescription drugs including antipsychotics (Thorazine)

The anesthetic Diprivan

Chronic poisoning from mercury or lead

Urine color affected by beets. Jmarchn/CC BY-SA 3.0


Strenuous exercise in addition to fierce stationary bike pedaling, such as distance running and jumping drills.

Distance runners are most at risk, but those who do any strenuous exercise involving the lower body can have urinary bleeding.

Urinary tract infections

Cancer of the kidney or bladder (occasionally)

Visible hematuria in children can be caused by a kidney inflammation from a viral or bacterial infection.

See a doctor when:

1     Two or more incidents of the symptom occur, regardless of time lapse in between.

   Visible hematuria lasting beyond 24 hours

3     Urine color changes are not triggered by medications, dyes or food.

Dr. Stephenson’s clinical and research focus is the treatment of prostate, bladder, kidney and testes cancer. He has published over 100 articles in peer-reviewed journals.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer. 
Top image: Shutterstock/Eag1eEyes