What is microscopic hematuria?
"Microscopic" means something is so small that it can only be seen through a special tool called a microscope. "Hematuria" means blood in the urine. So, if you have microscopic hematuria, you have red blood cells in your urine, but you can’t see the blood when you urinate.
Causes & Risk Factors
What are some common causes of microscopic hematuria?
Here are some common causes of blood in the urine:
Urinary tract (bladder) infection
Swelling in the filtering system of the kidneys (this is called "glomerulonephritis")
A stone in your bladder or in a kidney
A disease that runs in families, such as cystic kidney disease
A blood disease, like sickle cell anemia
A tumor in your urinary tract (this may or may not be cancer)
Exercise (when this is the cause, hematuria will usually go away in 24 hours)
Diagnosis & Tests
How will my doctor check for microscopic hematuria?
Your doctor will usually start by asking you for a urine sample. He or she will test your urine (urinalysis) for the presence of red blood cells. Your doctor will also check for other things that might explain what is wrong. For example, white blood cells in your urine usually mean that you have an infection. If you have blood in your urine, your doctor will ask you some questions to find out what caused it.
If the cause isn’t clear, you may have to have more tests. You might have an ultrasound or an intravenous pyelogram (this is like an X-ray). A special tool, such as a cytoscope or an endoscope, may be used to look inside of your bladder. These tests are usually done by a urologist.
How do I give a urine sample?
A nurse will give you an antiseptic wipe (to clean yourself) and a sterile urine collection cup. In the bathroom, wash your hands with soap and warm water first.
For women: Use the antiseptic wipe to clean your vagina by wiping yourself from front to back 3 times before you urinate. Fold the wipe each time you use it, so that you are wiping with a clean part each time.
For men: Use the antiseptic wipe to clean the head of your penis. If you’re not circumcised, pull the foreskin back behind the head of the penis before you use the wipe. Move the wipe around the head of your penis before you urinate.
Start urinating in the toilet. About halfway through the urination, start catching the urine in the cup.
Wash your hands with soap and warm water.
Give the sample to the nurse. Someone will look at your urine under a microscope to see if it has blood in it.
What will my doctor do if I have microscopic hematuria?
If the cause of the blood in your urine is clear, your doctor will probably treat you. Then your doctor will check your urine again to see if the blood is gone. If it’s not, your doctor may perform more tests or refer you to a urologist.
Remember that it is always important to find out the cause of blood in your urine.
Questions to Ask Your Doctor
What treatment is best for me?
What is causing the blood in my urine?
Could I have a kidney stone?
Are there any medicines that I can take?
Will I need surgery?
How often do I need to come back for a follow-up visit?
Could I have cancer?
Evaluation of Asymptomatic Microscopic Hematuria in Adults by TR Thaller, M.D. and LP Wang, M.D.( 09/15/99, http://www.aafp.org/afp/990915ap/1143.html)
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.