In this lecture, we’re going to review
hematuria and also glomerulonephritis.
So let’s start with hematuria.
Hematuria can be either
gross or microscopic.
Gross means you can
simply see the blood
and microscopic hematuria is when
we see it under the microscope.
Generally, more than 5 cells per high-powered
filed tells you that there is hematuria.
About 0.5-2% of school age children
will, at one point, get hematuria,
so this is not an
But we have to remember when
we’re checking for hematuria
that not everything that's
red in pee is blood.
Rhabdomyolysis or breakdown of
muscle can look like blood,
Patients on certain drugs
such as pyridium or rifampin
can have dark or almost
Likewise, dyes; if a patient were to say,
eat something with a lot of red dye,
they may have urine
that looks like blood.
may look like blood
though those are often
abnormal if you find them.
So things like porphyria or high bilirubin
levels or patients with tyrosinimia.
Likewise, some foods if
eaten in large quantities
such as beets or blackberries can
cause a bloody-looking urine.
And in infants, this is common,
there can be a little red spot
in the front of the diaper
that parents may think
is blood in the urine,
but is in fact urate crystals and those are
common in infants and found in the diaper.
Also there maybe blood but is
not coming from the urine.
In older girls, menses may
come out in the urine sample
and appear to be blood or blood
maybe from the stool as well.
So when you see a patient with hematuria,
there’s a few questions you want to ask.
You need to ask if there was a recent
sore throat or recent skin infection
because this patient may have
You should ask about fever,
dysuria or flank pain,
that maybe a sign of pyelonephritis
or kidney infection.
A patient with nephritic syndrome
or significant renal involvement
may have high blood pressure.
So asking about blood
pressure is important.
It’s important to ask about a family
history of deafness or renal disease.
Remember, Alport syndrome which is which
is X-linked can happen in these patients
and can be familial, resulting
in renal disease and deafness.
It’s important to ask about
other chronic medical problems.
For example, patients with sickle cell or
lupus may present with blood in their urine.
Also ask about any history
of a purpuric rash,
palpable purpura over the legs or buttocks
area could be Henoch-Schonlein purpura
which absolutely presents
with blood in the urine
and that is in fact the
symptom we worry about.
Lastly, of course, a history of trauma.
If there is trauma to anywhere
on the urinary tract,
one can have bleeding that
comes out in the urine.
So hematuria is really a
It could be from
or it could be from somewhere
localized in the renal tract.
Let’s go through what your differential
would be for all of these various problems.
So multisystem diseases that can
cause hematuria include lupus,
either Wegener's or
hemolytic uremic syndrome,
sickle cell disease
or HIV nephropathy after the patient
has been sick for a period of time.
Patients may have tubular disease
in their kidneys, in the tubules,
and that can include pyelonephritis,
acute tubular necrosis, say after
someone took some ibuprofen,
or papillary necrosis.
Patients may also have vascular
disease in the kidneys
which could include arterial or
venous thrombi or an aneurysm
or perhaps a hemangioma in a patient
with significant hemangiomas.
There can be anatomic disease that’s
causing abnormalities in the kidney
which can then be damaged
and have some hematuria.
Examples would be hydronephrosis
or polycystic kidney disease.
Patient may have multicystic dysplasia
or tumors or some sort of renal trauma.
Lower down in the urinary tract,
patients may have stones, cystitis,
urethritis, trauma or bladder tumor.
Sometimes, a simple virus
can cause a cystitis
which causes blood in the urine
and this resolves of its own.
Occasionally, patients have isolated
renal disease that can cause hematuria.
The most common is
We already mentioned Alport syndrome
and post-strep glomerulonephritis,
but there are other glumerulo
diseases that can happen.
These include focal segmental
or patients may get
benign familial hematuria
which is a thin membrane disease
that persists in families.
When we think of the glomeruli
as causing disease,
we like to break things down into either
a primary protein spilling disease
or a primary blood
What we’ll do is we’ll check patients for
their urine and we will do urine dipstick.
That urine dipstick will tell us whether
there is protein, blood or both.
Classically, we are taught that there
are certain diseases that are nephrotic
such as focal segmented
and other diseases that are nephritic
such as post-strep glomerulonephritis.
And that these will present with either
protein spilling or blood spilling.
But the reality is more like this
slide, there is some overlap.
Oftentimes, patients can spill both but one
issue is more predominant than the other.
So if we see a patient
there are some urine
studies we need to do.
First, we need to look for signs
of urinary tract infection such as
white blood cells in the urine or
nitrites or leukocyte esterase.
Remember, nitrite is 99% specific.
So if you see blood in
the urine and nitrites,
this is almost definitely
urinary tract infection.
Less specific are
those other findings.
The urine electrolytes may be helpful in
patients where you suspect kidney stones
especially if you were to get
a calcium to creatinine ratio
which can tip you off that this patient
has hypercalciuria resulting in stones.
We usually will get a Chem 7 on these
patients and for a variety of reason.
The Chem 7 is important to check for
renal failure and ongoing renal problems
with renal damage and so, a BUN
and creatinine will be key.
Also in end-stage renal disease, you can
see other problems such as hyperkalemia.
The CBC is important to check for blood
loss if this is an ongoing problem
and again, that high white count may
be indicative of a pyelonephritis.
In patients with post-strep
MPGN or lupus or other
disease that are systemic,
you may see low complement levels and that
can be a clue that something is going on.
The renal ultrasound is first
line for most renal imaging.
So if we have a patient where we
suspect there is renal involvement,
the ultrasound is
usually where we start.
We really limit the CT for
things like renal stones,
although renal stones can absolutely
be imaged on ultrasound as well.
Occasionally, we will use a
that’s really for use in
and in particular, for diagnosing what
type of hydronephrosis is going on.
The VCUG is a little bit of
radiation and is fairly painful,
so we want to limit its use.
Cystoscopy is important for when
we suspect a bladder bleed,
especially a bladder bleed
of undetermined etiology.
We might want to look
for what the source is.