Hematuria is simply the medical term that doctors use for blood in the urine. Hematuria has multiple causes, and all causes of blood in the urine need to be evaluated by a urologist. Blood is divided into three broad categories: gross hematuria, microscopic hematuria, and dipstick positive hemoglobinuria.
There are other causes of colored urine besides blood.
Multiple foods, medications, medical conditions, as well as dehydration, can change the color of your urine.
The color and the odor of one’s urine are the most obvious characteristics to lay-people. Doctors are more concerned about how this relates to a microscopic evaluation of the urine for evidence of infection, stones, or cancer. Odor alone is rarely a first sign of urinary infection but most often is of little meaning if no other symptoms, such as pain, burning on urination, or frequent urination, are present.
The color of the urine is most commonly associates with the person’s state of hydration/dehydration. A well-hydrated person’s urine will be almost colorless while significantly dehydrated urine will have a very dark almost orange color. Dehydration is caused by not drinking enough fluid as well as by increased loss of fluid from sweating, diuretics, vomiting, and diarrhea.
The color of urine is affected by dehydration, foods such as asparagus, and by medications such as AZO, Pyridium or Phenazopyridine, and methylene blue for urinary pain. Multiple medications and foods can also change the color of your urine. Beets, which contain betalain, rhubarb, and blackberries will often change the urine to a pink or red color.
Urine color may be a sign of illness. Blood changes the urine red if the bleeding is fresh, but slow bleeding may change the urine to coffee, tea, or Coke-colored brown. Brownish urine my also be caused by fava beans and sometimes rhubarb. Liver disease such as hepatitis may make the urine a very dark yellow to brownish tint. Beta-carotene from carrots and supplements and high-dose vitamin C may cause the urine to be orange. In some people, the consumption of high-dose B vitamins and asparagus may occasionally turn the urine green.
Odor of urine is affected by medications and foods. Asparagus causes some people’s urine to have a strong odor. Urinary infection may be associated with a change in urine odor. Antibiotics frequently change the odor of urine. Diabetes is said to give the urine a sweet smell. Dehydration and some infections increase the amount of ammonia smell in the urine.
For a full list of foods, medications, and medical conditions that may change the color of your urine, scroll to the bottom of this page.
Back to hematuria:
The initial test on urine done by all doctors’ offices is the chemical dipstick test. This is a plastic stick with small pads attached. Each pad is impregnated with a different chemical. These pads change color in the presence of the substance they are specified to detect. They look for blood, pus, protein, nitrite, and several other factors commonly found in urine. The darker the shade the indicator color turns the more of that substance there is in the urine.
Gross hematuria is the most bothersome to both the patient and the urologist. It takes very little blood to turn the urine red. Seeing a little, red urine is enough to see the urologist. Even seeing the redness once is enough to see a urologist. This is not, however, an emergency. You do not normally need to go to the emergency room or call the doctor after hours.
Microscopic hematuria is usually found by a chemical dipstick and further evaluated in the laboratory by a microscopic examination of the urine confirming the presence of visible red blood cells (RBCs). Normal centrifuged and concentrated urine will have 0-3 RBCs per high-powered microscopic field (HPF). The centrifuged drop of urine is usually viewed at 400 power magnification. More RBCs than 0-3 need an evaluation.
Dipstick positive hematuria or hemoglobinuria is found on chemical testing, but there is no corresponding increase in number of RBCs found on microscopic examination. This is because dissolved hemoglobin is found by the chemical dipstick. This is a color change test. The yellow pad on the dipstick turns to progressively darker shades of green in the presence of hemoglobin or blood. It is currently thought that the filtration process in the kidney is breaking open RBCs, and the internal hemoglobin is released and dissolves. If there is no associated protein increase in the urine or if there is a history of difficult to control hypertension, monitoring this alone with serial microscopic urinalyses is all that is needed. If the hematuria is associated with proteinuria and hypertension, it may need to be evaluated by the medical kidney doctor, the nephrologist. Hemoglobinuria is found in about 5% of the adult population.
Dipstick positive hematuria:
Unless this is associated with malignant hypertension and more than a trace of protein in the urine, there is usually no cause for alarm. Dipstick positive hemoglobinuria simply needs monitoring. Usually this monitoring will be for a period of two to three years and all that’s needed is periodic visits to the urologist’s office for a simple, painless microscopic RBC evaluation. We like to refer to this visit as your “pee in a cup” visit. Repeating the microscopic urinalysis is all you may be asked to do. Unless associated with some other urologic problem such as recurrent infections, stones, or history of bladder problems, no cystoscopy or CT scan is usually required. Heavy protein associated with severe hypertension may be a sign of kidney disease. These people may need to see the nephrologist. The nephrologist is the medical kidney doctor. Urologists are the surgical kidney doctors.
Gross and Microscopic Hematuria evaluation:
Many things can put blood in the urine. While the most common things are benign, there are some cancers of the urinary tract that must be ruled out. Initial evaluation consists of an x-ray, a visual inspection of the bladder, and possibly some urine tests. X-ray examinations of the upper urinary tract can be accomplished with a CT urogram or an intravenous pyelogram (IVP). Both are used to look for stones, birth defects, and cancers of the kidneys and ureters.
The visual examination of the bladder is called a cystoscopy. This is required to look for polyps, stones, infections, prostatic bleeding, and cancer of the bladder. After introduction of Lidocaine anesthetic gel into the urethra in men or applied to the scope in women, the telescope is inserted into the bladder. This is not the rigid metal 7 millimeter telescope of the 1980s. The telescope has been flexible for many years now. The Flexible scope is a 5 millimeter scope. The average catheter inserted at surgery or on hospital admission is 5.3 to 6mm. Cystoscopy is a telescopic evaluation done in the urologist’s office. A thin, flexible telescope is guided through the urethra into the bladder. In men, both the prostate and the bladder are inspected. Inspection usually takes less than 2-3 minutes. The bladder is lined by mucosa. The lining looks much like the inside of the oral cavity or eyelid. Abnormalities as small as 2-3mm are easily seen.
Some burning on urination following the cystoscopy may occur. This usually lasts for 2-3 urinations. The urine infection rate from simple out-patient cystoscopy is about 1%. On occasion, you may see blood in the urine for less than a day. If the burning lasts more than 24 hours, you should call your urologist. You may be infected.
Urine tests for cancer such as a visual Pap smear of the urine or urinary cytology may be ordered. Several other chemical markers are also available but may not be needed. These include Nuclear Matrix Protein #22 (NMP-22) and FISH assay (fluorescence in situ hybridization).
Long-term follow-up for up to 3 years is recommended if the initial evaluation is negative. This usually consists of repeated microscopic urinalyses in the office but may require repeat X-rays in some patients. If the number of RBCs increases on serial urinalyses over time, there may be something in the urinary tract that was too small to find the first time around. In this case, the x-rays and cystoscopy may need to be repeated.
Causes of Hematuria
There are multiple causes of blood in the urine. They range from urinary stone disease (stones in the kidney, ureter, and bladder) to prostatic problems to infections. All of the above are far more common than cancers of the kidney, bladder, and prostate, which most patients are worried about. All people with blood in their urine should be evaluated by a urologist as soon as symptoms present.
Foods, Medications, and Medical Conditions that may change the color of your urine
Red, orange urine from medication
Adriamycin, doxorubicin, Chemotherapy
Betacarotine, suppliments, carrots
dihydroergotamine, migraine medication
isoniazid, tuberculosis treatment
phenazopyridine, Pyridium, Azo
riboflavin, vitamin B2
rifampin, antibiotic, anti tuberculosis
salycilates, Aspirin class medications
warfarin with out bleeding
Foods that turn urine red, orange
Medical conditions , urine red, orange
nephrolitiasis, kidney stones
Vaginal contamination, bleeding, period
Black, Brown urine from medication
alpha-methyldopa, Aldomet, BP med
bismuth, Pepto bismol
chloroquine, antimalarial medication
L-dopa, Parkinsons disease medication
nitrofurantoin, Macrobid, Macrodantin
primaquine, antimalarial medication
quinine, anti malarial medication
riboflavin, vitmin B2
sulfonamides, Bactrim, Septra, Sulfa drugs
Tylenol, acetominophen overdose
Foods that turn urine Black, Brown
Medical conditions , Black, Brown
cresol, some plastics
Melanoma, metastasis to the urinary tract
Blue green urine from medication
phenol, throat spray, EU not USA
Foods that turn urine blue green
Blue dye #1, food coloring
Clorets breath mints
Medical conditions blue, green
pseudomonas UTI, blue diaper synd
tryptophan, abnl metabolsim with UTI
Purple, blue urine
Blue diaper syndrome is the same, similar
Gram negative UTI, indole metabolism may
porphuria when exposed to sunlight
turn the catheter tubing blue
Calcium phosphate cyrstals, normal
Chyluria, lymphatic fluid in the urine
Funguria, yeast infection, candidiasis
Lipiduria, fat, cholesterol, trigycerides
mineral sediment hypercalcuria
mineral sediment hyperoxaluria
mineral sediment phosphatuira
puyria, infection, pus