UTI or Cancer: What To Know About Blood in the Urine

Leukocytes in the urine in low levels can be a normal finding. However, high levels of leukocytes in the urine can be caused by a UTI, kidney problems, lupus, or even cancer.

Leukocytes in Urine: Normal Range, Causes and Testing

Leukocytes in the urine in low levels can be a normal finding. However, high levels of leukocytes in the urine can be caused by a UTI, kidney problems, lupus, or even cancer.

High amounts of leukocytes in the urine are usually detected in a a urinalysis (also known as a “routine and microscopy” or “R and M”). This urine tests also looks other urine characteristics, like red blood cells, epithelial cells, microorganisms and proteins, all which can help to identify a diagnosis.

It is normal to have 0 to 5 leukocytes per microscopic field or 10,000 leukocytes per ml of urine – this range is not considered to be significant. However, the doctor may order further testing if other abnormalities are noted in the urine (e.g. blood, epithelial cells or foul odor) or if the patient presents with symptoms, like burning with urination, abdominal pain, or interrupted urine strep.

Normal range

The normal levels of leukocytes in the urine is 0 to 5 leukocytes per field. There may be higher amounts in women depending to their age and menstrual cycle.

When there are more than 5 leukocytes per field, the sample is identified as “pyuria”, which describes that there are high levels of leukocytes in the urine. In these cases, it’s important for the doctor to compare the pyuria with other results in the urine test, as well as compare urine results with the results of the blood tests and the microbiological tests that he or she may have requested.

What causes leukocytes in the urine?

Leukocytes can be noted in the urine for the following reasons:

1. UTI

A urinary tract infection (or UTI) is the most commonly occurring reason for increased levels of leukocytes in the urine. High levels indicate that the immune system is trying to fight off a fungal, bacterial or parasitic infection by fungus.

With infection, other characteristics will also be noted in the urine, such as the presence of epithelial cells and the microorganism responsible for the infection. Learn more about UTI symptoms and check-out our online symptoms quiz to assess your risk.

What to do: If infection is suspected, the doctor will likely order a urine culture test, which is a urine test that attempts to isolate and identify a possible microorganism that is causing the infection. Depending on the microorganism, the doctor will then recommend indicated treatment. If a bacterial infection is confirmed, for example, and the patient is symptomatic (e.g. pain and burning with urination, discharge, etc.), the doctor may prescribe antibiotics. Read more about the UTI treatment options your doctor may consider.

If a fungal infection is confirmed, the doctor will likely prescribe antifungal medication, such as fluconazole or miconazole. The medication chosen depends on the type of fungus identified. If parasites are the cause of the infection, (e.g. Trichomonas sp, which is the most common type of parasitic infection), the doctor will likely treat with metronidazole or tinidazole.

2. Kidney problems

Kidney dysfunction, as is seen with nephritis or kidney stones, can also cause elevated levels of leukocytes in the urine. Kidney problems can also leads to crystals in the urine or, sometimes, red blood cells.

Both nephritis and kidney stones may also present with some characteristic symptoms such as back pain, difficulty peeing and decrease in the quantity of urine.

What to do: If you suspect you have kidney stones or nephritis, it’s important to see your doctor or a urologist. They will likely order an ultrasound and urine testing in order to identify the the reason for the increase in leukocytes and start the appropriate treatment. Complete our online kidney symptoms quiz to determine your risk for kidney disease.

3. Systemic lupus erythematosus

Systemic lupus erythematosus is an auto-immune disease, which means it’s a condition where the immune cells attack the body, causing joint, skin, eye and kidney inflammation. In the presence of this disease, urine testing will often show high levels of leukocytes. This combined with CBC blood testing can help with diagnosis.

Learn more about the symptoms of lupus and what can cause it.

What to do: Correcting leukocyte levels in the urine is typically done under medical supervision. Usually, the doctor will prescribe medication according to the symptoms presented by the patient, such as anti-inflammatory medication, corticosteroids, or immunosuppressive drugs. In short, by managing symptoms related to lupus, it is possible to decrease urine leukocyte levels.

4. Use of medication

Some types of medication, such as antibiotics, aspirin, corticosteroids, and diuretics can cause elevated leukocyte levels in the urine.

What to do: If you are taking any type of medication that may be causing an increase of leukocytes in the urine, it’s important to bring your concern to your prescribing doctor.

5. Holding urine

Holding urine for long periods of time can promote the growth and development of microorganisms, resulting in a urinary tract infection and causing leukocytes to appear in the urine. In addition, if you hold urine for too long, your bladder will begin to weaken overtime and eventually will be unable to empty completely. This causes urine to pool inside the bladder, causing microorganisms to grow.

What to do: If you suspect this might be the cause, it’s important that you relieve yourself as soon as you feel the urge to pee. This will prevent the accumulation of urine and microorganisms in the bladder. In addition, to prevent infections from occurring, it is recommended that you drink at least 2 liters (about 8 cups) of water per day.

6. Cancer

Although it is not as frequently occurring, bladder, prostate or kidney cancer can weaken the immune system and lead to elevated leukocyte levels in the urine. In addition, leukocytes can appear as a side effect of cancer treatment.

What to do: The presence of leukocytes in the urine is common finding in urinary tract or genital cancers. If you have cancer and your levels happen to be elevated, your doctor will likely keep checking urine leukocytes levels as a way of tracking disease progression as well as your body’s response to treatment. Read more about the cancer blood tests your doctor may order to rule out this disease.

Urine tests

The urine leukocyte levels are verified through macro and microscopic analysis, which identifies the presence of abnormal characteristics, such as crystals, epithelial cells, mucous, bacteria, fungi, parasites, leukocytes and red blood cells.

Before carrying out a microscopic test, the reagent test is done to indicate certain characteristics of the urine, including the leukocyte esterase, which is a reagent when there are a lot of leukocytes in the urine. Even though this signals pyuria, it’s important that the quantity of leukocytes seen in the microscopic test be communicated.

UTI or Cancer: What To Know About Blood in the Urine

Surgeon and urologic cancer specialist Eugene Pietzak says anyone who detects blood in the urine should notify their primary care doctor or a urologist to investigate it further.

• Blood in the urine can be a sign of infection, kidney stones, or cancer, especiallybladder cancer.
• Anyone with blood in their urine should have a doctor investigate the cause.

Blood in the urine, also called hematuria, is a sure sign that something is wrong. But it can be hard to tell what caused this symptom. Is it just a urinary tract infection (UTI), which can be treated with antibiotics, or something more serious, like cancer?

Here’s what you should know about blood in the urine — and why you should never ignore it.

Two Types of Blood in the Urine

The two types of blood in the urine (hematuria) are:

• Gross hematuria — when the blood is visible. It may be very faint with a pink tinge, or the blood may be obvious. The color comes from hemoglobin in red blood cells. The blood may not be present in the urine all the time — it may come and go.
• Microscopic hematuria — the urine appears normal, but an increased number of red blood cells can be seen under a microscope. This symptom may show up on a urine analysis you would have as part of an annual physical or any standard checkup.

What Causes Blood in the Urine?

There are several possible causes for this symptom, explains Memorial Sloan Kettering Cancer Center (MSK) surgeon and urologic cancer specialist Eugene Pietzak.

• Urinary tract infections. UTIs are more common in women than men, explains Dr. Pietzak, because a woman’s urethra (the tube from the bladder to where the urine comes out of the body) is shorter than a man’s. This makes it easier for bacteria to get into the bladder or kidney. Occasionally, a UTI can cause an increase of white blood cells in the urine, a condition known as pyuria. This can cause the urine to appear cloudy, but it is not what most people think of as “blood in the urine.”
• Bladder or kidney stones. Solid masses that form from chemicals in the urine might scrape the lining of the bladder or kidney and damage blood vessels, causing them to leak.
• Cancer of the bladder, kidney, or prostate. “A tumor may grow, and the blood vessels within it become fragile so that they rupture and bleed,” Dr. Pietzak says. “I’ve heard people tell vivid stories of having normal urine and then suddenly it becomes completely red.”
  • Often, the person has had no other symptoms before the blood appears. The most likely cancer is bladder cancer, although the blood also could be a sign or kidney cancer (renal cell cancer) or prostate cancer.
  • Blood in the urine is more likely to be cancer in men than in women, mainly because men develop bladder cancer at a much higher rate — about four times as much — than women. Unfortunately, this often leads women (and their doctors) to dismiss this cancer warning sign when the disease is at an early stage.

  What To Do if There Is Blood in Your Urine

  Whether it is gross hematuria or microscopic hematuria, you should not ignore it, Dr. Pietzak emphasizes. Notify your primary care doctor, who can refer you to a urologist for a more thorough evaluation. The primary care doctor or urologist will order tests to help determine whether it is a UTI. This involves examining urine under a microscope for bacteria or white blood cells, which are signs of infection. A urine culture may also be taken to detect and identify bacteria and yeast in the urine.

  Any visible blood in the urine is abnormal.
  Eugene Pietzak surgeon and urologic cancer specialist

  When Blood in the Urine Means UTI

  If a UTI is detected, antibiotics are usually the first treatment and are effective at clearing up the infection.

  When Blood in the Urine Means Cancer

  If no UTI is detected, the doctor may do a test called a urine cytology, which checks for cancer cells. “If it comes back positive or suspicious for cancer cells in the urine, that is very concerning,” Dr. Pietzak says. Patients also may have an imaging test, such as a CT, an ultrasound, or an MRI to look for abnormal growths in the bladder or kidney.

  If you notice blood in the urine yourself, do not delay getting it checked out, even if it seems to go away.

  “Any visible blood in the urine is abnormal,” Dr. Pietzak says. “In the cancer patients we treat, we often hear horror stories where someone noticed blood and even the primary care doctor was notified but no lab workup or evaluation was done for a long time. If someone does have bladder cancer, the earlier it is detected, the less intense the treatment needs to be.”

  If you have cancer, Dr. Pietzak recommends treatment at a specialized cancer center such as MSK. “We have various treatment options and clinical trials that aren’t available at most places,” he says. “This allows us to tailor our care to the individual patients. We also have an active research program that is trying to understand the biology of cancer. This includes looking at mutations in urine to make it easier to diagnose what’s happening — including whether the blood in the urine is from cancer or another cause.”

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