Blood in Urine
Free Symptom Checker
with Physician-supervised AI
Worried about your symptoms?
Start the Blood in Urine test with our free AI Symptom Checker.
This will help us personalize your assessment.
By starting the symptom checker, you agree to the Privacy Policy and Terms of Use
Try one of these related symptoms.
Gross hematuria
Abdominal pain
Cloudy urine
Frequent urination
Lower abdominal pain
Foamy urine
Blood clots in urine
Burning sensation when urinating
Bleeding from the urethra
Red brown urine
Pee mixed with blood
About the Symptom
Bloody urine (hematuria) describes frank blood or visible blood in the urine. The urine may appear bright red or brownish.
When to See a Doctor
Seek professional care if you experience any of the following symptoms
- Bloody or red urine
Possible Causes
Generally, Blood in urine can be related to:
- Hereditary Nephritis (Alport Syndrome)
A rare genetic disorder characterized by progressive kidney disease and abnormalities of the inner ear and the eye. It usually presents as blood in the urine, high blood pressure and swelling (edema).
- Bladder Cancer / Ureteric Cancer / Renal Pelvis Cancer
Cancer of the walls of the urinary system. Risk factors include smoking, age, and exposure to certain chemicals. in addition people over 55, people who have been treated for cancer in the past with certain chemotherapies or radiation to the area are also at higher risk. Symptoms depends on location of the tumor but blood in the urine -- whether seen by the naked eye or seen under the microscope -- is the most common symptom. Painful or frequent urination or flank pain can also be warning signs.
- Renal Cell Carcinoma
Renal cell carcinoma is another name for kidney cancer, a cancer that originates in the kidneys. The exact cause is unknown, but smoking and certain kidney diseases and hereditary syndromes are risk factors. Many times there are no symptoms and the tumor is found on a x-ray test performed for another reason. Sometimes patients have blood in the urine or back or side pain.
- IgA Vasculitis (Henoch-Schonlein Purpura)
- Polycystic Kidney Disease (PKD)
- Paroxysmal Nocturnal Hemoglobinuria
- Vasculitis (including Cryoglobulinemia)
- Polymyositis / Dermatomyositis
Related Serious Diseases
Sometimes, Blood in urine may be related to these serious diseases:
- Acute Glomerulonephritis
A type of kidney inflammation that causes an abnormal loss of blood or protein in the urine. It can be caused by infection (bacterial or viral) or other illnesses like lupus, Goodpasture's syndrome, Wegener's disease, and polyarteritis nodosa.
- Renal Infarction
Doctor's Diagnostic Questions
Your doctor may ask these questions to check for this symptom:
- Do you have blood in your urine?
- When did you first notice blood in your urine?
- How often do you notice blood in your urine?
- Does your urine appear red or bloody in the morning?
Reviewed By:
Kenji Taylor, MD, MSc (Family Medicine, Primary Care)
Dr. Taylor is a Japanese-African American physician who grew up and was educated in the United States but spent a considerable amount of time in Japan as a college student, working professional and now father of three. After graduating from Brown, he worked in finance first before attending medical school at Penn. He then completed a fellowship with the Centers for Disease Control before going on to specialize in Family and Community Medicine at the University of California, San Francisco (UCSF) where he was also a chief resident. After a faculty position at Stanford, he moved with his family to Japan where he continues to see families on a military base outside of Tokyo, teach Japanese residents and serve remotely as a medical director for Roots Community Health Center. He also enjoys editing and writing podcast summaries for Hippo Education.
Nao Saito, MD (Urology)
After graduating from Tokyo Women's Medical University School of Medicine, Dr. Saito worked at Tokyo Women's Medical University Hospital, Toda Chuo General Hospital, Tokyo Women's Medical University Yachiyo Medical Center, and Ako Chuo Hospital before becoming Deputy Director (current position) at Takasaki Tower Clinic Department of Ophthalmology and Urology in April 2020.
Content updated on Feb 7, 2025
Following the Medical Content Editorial Policy
Was this page helpful?
Tell your friends about us.
We would love to help them too.
Just 3 minutes.
Developed by doctors.
Try Free Symptom QuizHow Ubie Can Help You
With a free 3-min Blood in Urine quiz, powered by Ubie's AI and doctors, find possible causes of your symptoms.
This questionnaire is customized to your situation and symptoms, including the following personal information:
Biological Sex - helps us provide relevant suggestions for male vs. female conditions.
Age - adjusts our guidance based on any age-related health factors.
History - considers past illnesses, surgeries, family history, and lifestyle choices.
Your symptoms
Our AI
Your report
Your personal report will tell you
✔ When to see a doctor
✔︎ What causes your symptoms
✔︎ Treatment information etc.
People with similar symptoms also use Ubie's symptom checker to find possible causes
- Red-brown urine came out
- Blood from the urethra
- Blood is mixed in pee
- Urine is red-brown
- Blood in urine
Find Similar Symptoms
Similar symptoms or complaints
Symptoms from similar body parts
Symptoms treated by the same specialty
FAQs
Q.
BUN Normal Range (By Age)
A.
BUN normal ranges by age: newborns 0–2 months 3–12 mg/dL; infants and children 2 months–12 years 5–18 mg/dL; adolescents 13–17 years 7–20 mg/dL; adults 18–59 years 7–20 mg/dL; older adults 60+ years 8–23 mg/dL. There are several factors to consider. Ranges can vary by lab and many things affect BUN, including hydration, protein intake, medications, liver and kidney function, and it should be interpreted with creatinine; if your result is outside the range or you have symptoms, speak with a clinician. See below for important details and next steps.
References:
* Alagoz, H., Inal, M., Kucuk, O., Cimen, O. B., & Ozer, I. (2018). Reference intervals for serum urea nitrogen and creatinine in different age groups. *Journal of Clinical Laboratory Analysis*, *32*(1), e22216.
* Adeli, K., Higgins, V., Trajcevski, K., & White-Rose, P. (2011). Pediatric reference intervals for routine chemistry analytes based on a healthy population from the CALIPER study. *Clinical Chemistry*, *57*(10), 1380-1387.
* Zhu, Y., Lu, R., Zhao, J., Zhang, C., Cheng, X., Yang, S., & Li, R. (2012). Age-related changes in serum urea nitrogen, creatinine, uric acid, and phosphate. *Clinica Chimica Acta*, *413*(5-6), 601-603.
* Wu, Y., Jin, Q., Zhong, B., Zeng, H., Fan, G., Shi, Z., ... & Shao, Y. (2018). Reference intervals for common biochemical analytes in healthy adults in Zhejiang Province, China. *Clinical Chemistry and Laboratory Medicine (CCLM)*, *56*(2), 326-333.
* Gruson, D., Rousseau, J., & Vanpee, D. (2014). Reference intervals for routine clinical chemistry parameters in elderly outpatients. *Clinical Chemistry and Laboratory Medicine (CCLM)*, *52*(3), e67-e70.
Q.
BUN Test: What It Measures
A.
The Blood Urea Nitrogen BUN test measures the amount of urea nitrogen in your blood to assess how effectively your kidneys filter waste, while also reflecting liver function and your body’s fluid balance. There are several factors to consider, and results are best interpreted with creatinine, eGFR, and symptoms; see below for normal ranges, reasons BUN can be high or low, how to prepare, and when to seek medical care.
References:
* Coresh J, et al. Blood urea nitrogen (BUN) as a marker of kidney function. Curr Opin Nephrol Hypertens. 2018 Nov;27(6):448-454. doi: 10.1097/MNH.0000000000000446. PMID: 30283020.
* Al-Hussain A, et al. Urea cycle disorders: a metabolic overview. Arch Med Sci. 2022 Aug 10;18(6):1597-1607. doi: 10.5114/aoms/152912. PMID: 35948753; PMCID: PMC9731637.
* Delanaye P, et al. Biochemical markers of kidney function: Old and new. J Nephrol. 2019 Aug;32(4):493-502. doi: 10.1007/s40620-019-00624-3. PMID: 31109919.
* Meyer TW, et al. Uremia: a clinical perspective. Am J Kidney Dis. 2014 Dec;64(6):951-65. doi: 10.1053/j.ajkd.2014.05.024. Epub 2014 Jul 3. PMID: 24994781; PMCID: PMC4252684.
* Moeller S, et al. Measuring Kidney Function: Urea and Creatinine. Lab Med. 2019 May 1;50(2):100-105. doi: 10.1093/labmed/lmy048. PMID: 30678684.
Q.
BUN vs Creatinine: What’s the Difference?
A.
BUN and creatinine both assess kidney function, but they measure different waste products and respond differently to diet, hydration, muscle mass, and illness; creatinine is steadier and more specific to filtration, while BUN is more easily influenced. Doctors interpret them together and may use the BUN to creatinine ratio to help sort out dehydration, medication effects, liver or muscle problems, and true kidney disease. There are several factors to consider; for reference ranges, common causes of abnormal results, symptoms to watch, and when to seek care, see the complete details below.
References:
* Stevens, L. A., & Nolin, T. D. (2012). Creatinine: a suitable marker of kidney function? *Clinical nephrology*, *77*(3), 175–182. https://pubmed.ncbi.nlm.nih.gov/22460492/
* Portilla, D. (2014). Beyond creatinine and BUN: Novel biomarkers for detecting and predicting acute kidney injury. *Advances in clinical chemistry*, *64*, 141–157. https://pubmed.ncbi.nlm.nih.gov/24589993/
* Lameire, N. H., Van Biesen, W., & Vanholder, R. (2016). Acute kidney injury biomarkers: what's the future? *Current opinion in critical care*, *22*(6), 555–563. https://pubmed.ncbi.nlm.nih.gov/27040409/
* Inker, L. A., & Levey, A. S. (2015). Estimation of Glomerular Filtration Rate. *Journal of the American Society of Nephrology*, *26*(Suppl 1), S36–S47. https://pubmed.ncbi.nlm.nih.gov/26458145/
* Lameire, N., Van Biesen, W., & Vanholder, R. (2012). Creatinine clearance: an imperfect measure of glomerular filtration rate. *Clinical nephrology*, *77*(3), 183–185. https://pubmed.ncbi.nlm.nih.gov/22460493/
Q.
High BUN? Common Causes
A.
Common causes of a high BUN include dehydration, kidney disease or acute injury, high protein intake, gastrointestinal bleeding, reduced kidney blood flow, certain medications, and age-related changes. There are several factors to consider, and BUN is best interpreted with creatinine, urine tests, symptoms, and trends; see the complete details below to know when it is urgent, when it is likely reversible, and what next steps to take.
References:
* Barreto E, et al. Blood Urea Nitrogen (BUN). *StatPearls [Internet]*. 2023 Jan-. PMID: 29261962. https://pubmed.ncbi.nlm.nih.gov/29261962/
* Hsu RK, et al. Acute Kidney Injury: A Clinical Review. *JAMA*. 2018 Sep 25;320(12):1282-1294. PMID: 30252152. https://pubmed.ncbi.nlm.nih.gov/30252152/
* Webster AC, et al. Chronic Kidney Disease: A Review. *Lancet*. 2017 Jul 29;390(10090):183-193. PMID: 28214223. https://pubmed.ncbi.nlm.nih.gov/28214223/
* Singh I, et al. Obstructive Uropathy: Definition, Clinical Presentation, and Treatment. *Indian J Nephrol*. 2019 May-Jun;29(3):184-188. PMID: 31224956. https://pubmed.ncbi.nlm.nih.gov/31224956/
* Stevens LA, et al. Understanding and Interpreting Basic Kidney Function Tests. *Semin Nephrol*. 2014 Mar;34(2):161-7. PMID: 24785461. https://pubmed.ncbi.nlm.nih.gov/24785461/
Q.
Low BUN: Should You Worry?
A.
Low BUN is usually not dangerous, but the cause and your overall picture matter; it is often due to low protein intake, overhydration, or normal pregnancy changes, and less often to liver or hormone-related problems. Be more concerned if it is persistent or occurs with symptoms like fatigue, confusion, swelling, jaundice, or electrolyte abnormalities and review with your clinician to plan next steps; there are several factors and red flags to consider, so see the complete guidance below.
References:
* Guo X, Ma S, Li K, et al. Low blood urea nitrogen (BUN): A sign of severe liver disease and malnutrition or an ignored marker of other conditions? *J Clin Lab Anal*. 2020 Aug;34(8):e23376. doi: 10.1002/jcla.23376. PMID: 32662217.
* Zhang H, Wang X, Liu Q, et al. Reference interval of blood urea nitrogen: a systematic review and meta-analysis. *Ann Transl Med*. 2020 May;8(9):590. doi: 10.21037/atm.2020.04.18. PMID: 32585252.
* Luo J, Shi S, Liu F, et al. Low blood urea nitrogen levels are associated with adverse outcomes in critically ill patients with cirrhosis. *Hepatol Int*. 2019 Jan;13(1):79-88. doi: 10.1007/s12072-018-9907-2. PMID: 30107299.
* Dwyer JT. Blood urea nitrogen as an indicator of protein intake and nutritional status. *J Nutr*. 2007 Sep;137(9):2013-7. doi: 10.1093/jn/137.9.2013. PMID: 17769939.
* Chen Y, Yu P, Zhang J, et al. Blood urea nitrogen and creatinine during normal pregnancy: a systematic review. *BMC Nephrol*. 2020 Jul 2;21(1):271. doi: 10.1186/s12882-020-01934-w. PMID: 32620786.
Q.
Is there dna in urine?
A.
Yes, urine contains DNA. It includes DNA from shed urinary tract cells plus highly fragmented human cell-free and mitochondrial DNA and microbial DNA, with amounts that can be low and variable based on hydration, kidney function, infection, and time of day. There are several factors to consider; see below to understand more, including how sensitive tests detect it and how findings may guide bladder, prostate, or kidney cancer screening and monitoring, prenatal screening research, transplant surveillance, and infection testing, as well as important limitations and lab quality issues that could change your next steps.
References:
Lo YM, Chan LY, Lo KW, Tsui NB, Lai VV, & Wainscoat JS. (2001). Quantitative analysis of fetal DNA in maternal plasma and urine. Molecular Genetics and Metabolism, 10835152.
Wai CT, Greenson JK, Fontana RJ, Kalbfleisch JD, Marrero JA, Conjeevaram HS, & Lok AS. (2003). A simple noninvasive index can predict both significant… Hepatology, 14522744.
D'Amico G, Garcia-Tsao G, & Pagliaro L. (2006). Natural history and prognostic indicators of survival in cirrhosis… Journal of Hepatology, 16717258.
Ubie is supervised by 50+ medical experts worldwide
Our symptom checker AI is continuously refined with input from experienced physicians, empowering them to make more accurate diagnoses.
Ubie is recognized by healthcare and tech leaders
“World’s Best Digital
Health Companies”
Newsweek 2024
“Best With AI”
Google Play Best of 2023
“Best in Class”
Digital Health Awards 2023 (Quarterfinalist)
Which is the best Symptom Checker?
Ubie’s symptom checker demonstrated a Top-10 hit accuracy of 71.6%, surpassing the performance of several leading symptom checkers in the market, which averaged around 60% accuracy in similar assessments.
Link to full study:
https://www.medrxiv.org/content/10.1101/2024.08.29.24312810v1References
Saleem MO, Hamawy K. Hematuria. 2022 Aug 8. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 30480952.
https://pubmed.ncbi.nlm.nih.gov/30480952/#:~:text=Hematuria%20is%20defined%20as%20the,by%20the%20primary%20care%20provider.