DEAR DR. DONOHUE: For two years I have had blood in my urine, but I can’t see it. It’s detected with a urine test. I have seen a nephrologist (an internal medicine doctor specializing in kidney diseases) and a urologist (a surgeon whose specialty is the surgical correction of urinary tract problems), but no cause can be found. I don’t have bladder cancer. I have had every test possible. I see each doctor once a year. Could there be something that they can’t detect? – R.M.

ANSWER: Blood in the urine can turn the urine color dark brown or red, or it can be detected only by microscopic examination of the urine. Causes of urinary blood are many, and just for the sake of readers, I’ll include male causes too (the writer is a 32-year-old woman).

Many times, urinary tract infections are responsible for urinary blood. Glomerulonephritis – inflammation of the kidneys – is a cause with significant consequences. When it’s present, the urine also contains protein and red blood cell casts. Casts are like clay molds of kidney structures, only these molds are made from red blood cells. Clotting problems also can make red blood cells leak into the urine. The most important cause is cancer, but it’s not the most frequent cause. Prostate gland enlargement can lead to urine blood.

You have been under the care of a nephrologist and a urologist. I am confident that one of these doctors has ordered pictures of your kidneys and bladder, either with X-rays, ultrasounds or CT scans. If your urine showed findings of inflammation, the nephrologist would have insisted on a kidney biopsy. The fact that you say you don’t have bladder cancer suggests that the urologist examined your bladder with a cystoscope and found no cancer. I also take it that your blood tests show that your kidneys are functioning well.

In a rather large number of people like you – with blood in the urine and with a normal, thorough work-up – no source of bleeding is found. The only thing for you to do is have your annual exams so the doctors can pick up anything that might be incubating. It’s likely that nothing is.

DEAR DR. DONOHUE: I am a 76-year-old man in relatively good health and not on any blood thinners. For the past few years I have been getting dark blue bruises on my forearms and hands after I even lightly bump against something. It has been described as purpura. My doctor attributes this to aging, but some friends have warned me that it could be something as ominous as cancer. Do I have something to fear? – C.R.

ANSWER: “Purpura” is just a fancy word for a bruise, and many bruises result from spontaneous breaking of capillaries. Capillaries are tiny, fragile blood vessels that connect arteries to veins. Through capillaries, oxygen and nutrients are delivered to the body, and waste products are picked up for disposal. Aging makes fragile capillaries even more fragile, and it causes a loss of the supporting tissues that prop them up and cushion them. Therefore, many older people suffer the same fate you describe.

Even though you don’t take blood thinners, how about aspirin? It can cause easy bruising.

There’s an extremely small chance that a clotting disorder might be the problem. Discuss it with your doctor. A few lab tests can eliminate that tiny possibility. Cancer is not likely in your case. Cancer that has not been treated for two years would give you other symptoms. Aging is a good bet.

DEAR DR. DONOHUE: My husband is on pills for his elevated blood sugar. He is supposed to get a blood test after eight hours of fasting. He works the third shift (midnight to 8 a.m.). Should he come home, eat and wait eight hours while he sleeps, or should he wait eight hours from his last break at 3 a.m.? – B.S.

ANSWER: It would probably be better for him to go to sleep for eight hours before his blood is tested. That will eliminated the chances that he will get a lower blood sugar reading from his being active, something that will not occur if he gets his sugar checked after a night’s sleep.

Does your husband have an inexpensive little machine – a glucometer – that gives accurate blood sugar readings? He should. And he should check his sugar at other times, too, not just when he’s fasting.



Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.