hematuria
Meaning of hematuria: Color is a poor guide here, since beets and some medicines redden urine while a serious cause may leave it looking normal.
Definition of hematuria
Hematuria is the presence of red blood cells in the urine. Gross hematuria is visible, turning urine pink, red or brown, while microscopic hematuria shows up only when a sample is tested or examined under a microscope. The word records a finding rather than a diagnosis, since bleeding can start anywhere from the kidneys to the urethra.
How hematuria is built
- hem/o, hemat/o Combining form · Greek blood
- -uria Suffix · Greek condition of the urine
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
Where can the bleeding come from?
| Where it starts | Usual reasons |
|---|---|
| Kidney | Stones, inflammation of the filtering units, injury, cysts, tumors |
| Ureter and bladder | Stones, infection, bladder tumors |
| Prostate and urethra | Enlargement, inflammation, prostate cancer |
| The body as a whole | Clotting disorders and blood thinning medicines |
The list is long because the urinary tract is long, and a red cell can enter it at any point along the way. Bleeding from the filtering units of the kidney tends to arrive mixed evenly through the stream and often brings protein with it, while bleeding from the drainage system further down may appear only at the start or the end of passing urine, which is a clue to where along the route the source sits.
Is red urine always blood?
No, and the mistake runs in both directions. Beets, rhubarb, blackberries and some food dyes tint urine red, as do several medicines, one of which is given specifically to numb the bladder and turns it bright orange. Dark brown urine may come from bile rather than blood. In the other direction, two substances that are not red cells still turn a dipstick positive: hemoglobin released when red cells break apart inside the circulation, and myoglobin released from damaged muscle. That is why a positive strip is checked under the microscope. Finding no red cells there points away from the urinary tract altogether and toward one of those two.
Why does the pattern matter more than the amount?
Quantity says very little, because a small amount of blood colors a large volume of urine, and a trace visible only under the microscope can accompany a serious cause. What carries information is the company it keeps. Burning and urgency alongside bleeding suggest infection. Severe pain in the flank traveling toward the groin suggests a stone. Bleeding with no pain at all, particularly when it is visible, is the pattern most associated with a tumor of the urinary tract, which is why it is not dismissed for being painless. Bleeding that follows a sore throat by a week or two, or that arrives with swelling and protein in the urine, points instead at the filtering units. Strenuous exercise and a recent catheter are common innocent explanations, and bleeding in a person taking a blood thinner still prompts the same search, since the medicine tends to reveal a cause rather than be the whole of it.
Also known as
Used in a sentence
Urinalysis confirmed microscopic hematuria that was not visible to the patient.
Good to know
Red urine is not always hematuria, since foods, pigments and medicines can alter its color. The absence of pain does not make confirmed hematuria less significant, because bleeding from a urinary tract tumor is characteristically painless, while pain more often accompanies stones or infection.
Word origin
Where “hematuria” comes from
Built from Greek haima, hemat-, meaning blood, and -uria, denoting a condition of the urine.