Symptoms
Blood in urine: causes, warning signs and what to do
Is this an emergency?
This is not an emergency service. Call 911 or go to the nearest emergency room if you have:
- Severe pain in your side or back with fever, chills or vomiting
- You cannot pee, or only a little comes out with a lot of effort
- Blood clots in your urine
- A lot of blood, or you feel dizzy or weak
- Blood in your urine after a fall, blow or accident
Help lines
Blood in urine should never be ignored, even when it does not hurt. It often comes from a urinary tract infection or a kidney stone, but it can also be a sign of a bladder, kidney or prostate problem. Go to the ER if you have fever with back pain, clots or cannot pee. Otherwise, the doctor evaluates you by video and gives you a lab order.
Other names: Hematuria, Red urine
Possible causes
Urinary tract infection
With burning and needing to pee often
Enlarged prostate
Older men, weak stream, peeing at night
Kidney or bladder stones
Pain in waves in the side; we tell you where to go for imaging
Very hard exercise
Shows up after long-distance running and clears in a day or two
Blood thinners
The doctor reviews your medicines; do not stop them without advice
Bladder or kidney cancer
Sometimes painless blood; needs an in-person urologist evaluation
Foods and medicines that color urine
Beets and others; not blood
On this page(8)
When blood in urine is an emergency
For your safety, do not wait for a video visit: go to the emergency room or call 911 if you have any of these signs. See when to go to the ER.
- Severe pain in your side or back with fever, chills or vomiting
- You cannot pee, or only a little comes out with a lot of effort
- Blood clots in your urine
- A lot of blood, or you feel dizzy or weak
- Blood in your urine after a fall, blow or accident
What is blood in the urine (hematuria)?
Doctors call it hematuria. According to the NIH there are two kinds: blood you can see, when urine looks pink, red or tea-colored, and blood you cannot see that only shows up on a urine test.
The most common causes are an infection of the bladder, kidney or prostate, kidney or bladder stones, an enlarged prostate and very hard exercise. Blood thinners can also cause it. Less common but serious causes include bladder or kidney cancer and kidney disease. That is why MedlinePlus says never to ignore blood you see in your urine.
Are you sure it is blood? Beets, other foods and some medicines can turn urine red. In women, blood may come from a period rather than the urine. A urine test settles it.
How we help by video
You see Dr. Diana Nieves Castro, MD, a Puerto Rico–licensed general practice physician with several years of emergency-department experience, in English or Spanish. That experience matters here: she knows which cases are handled with tests and which need an ER now.
We evaluate, diagnose and treat. The doctor asks what your urine looks like, since when, whether it burns or hurts, whether you have a fever, whether you smoke or used to, and what medicines you take. We give you a lab order for a lab near you: urinalysis, urine culture and kidney blood tests, depending on your case.
If it is a urinary tract infection and it is appropriate, the doctor prescribes and we send your prescription to your pharmacy. If it looks like a kidney stone, we tell you where to go for imaging. If you can see blood and there are no signs of infection, especially if you smoke or are older, the doctor refers you to a urologist in person: that work-up is not closed by video.
Your doctor
Dr. Diana Nieves Castro, MD
General practice physician
Several years of emergency-department experience.
Founding Executive Director of The Health Initiative.
Your visit in 3 steps
Request a visit online 24/7 — we confirm your time by email or text.
Request your visit.
Book a visit and choose "Doctor visit". You pay by card when you request it.
See the doctor by video.
We send you a secure video link. It works on your phone, tablet or computer.
Get your plan.
A lab order, a prescription if appropriate and, if needed, an in-person referral.
What the visit costs
A doctor visit costs US$79, the same price for every age, with no membership. You pay by card when you request the visit, and you get a full refund if the visit can’t take place. The lab charges for the tests separately. For existing patients, reviewing the results the doctor ordered is a US$49 follow-up visit. See all prices.
Which tests are ordered and what happens next
The first step is almost always a urinalysis, which confirms whether there is blood and looks for signs of infection. Depending on your case, a urine culture and blood tests such as a blood count and creatinine are added.
According to the NIH, if the test confirms blood and there is no clear cause, the next step may be imaging (ultrasound or CT) and a cystoscopy, a look inside the bladder with a thin camera. Those tests are done in person: the doctor tells you which specialist you need and refers you.
According to the National Cancer Institute, smoking is a major risk factor for bladder cancer, and the risk goes up with age. If you smoke or used to, do not let blood in your urine slide, even if it went away on its own.
Blood in urine in children
In children, blood in the urine can come from a urinary tract infection, an injury, or kidney inflammation after a throat infection. The doctor evaluates your child by video with you on camera and gives you the order for a urine test. Patients under 21 need a parent or legal guardian on camera for the whole visit, with ID. For safety, go to the ER if your child has blood in the urine with a swollen face or legs, is peeing very little or has severe pain.
Frequently asked questions
Is blood in urine with no pain serious?
Could it be a urinary tract infection?
What if I think it is a kidney stone?
Why is my urine red if it is not blood?
About this page
Author: The Health Initiative
Medical care provided by Dr. Diana Nieves Castro, MD (PR license 24027)
Disclosure: Founding Executive Director of The Health Initiative
Published: 2026-10-02 · Updated: 2026-10-02
Sources (4)
- Blood in urine (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)
- Hematuria (Blood in the Urine) (NIDDK, NIH) (opens in a new tab) (accessed 2026-10-02)
- Bladder Cancer Causes and Risk Factors (National Cancer Institute) (opens in a new tab) (accessed 2026-10-02)
- Prostate Enlargement (BPH) (NIDDK, NIH) (opens in a new tab) (accessed 2026-10-02)