Blood Clots (cont.)
What are the symptoms of blood clots?
Venous clots do not allow blood to return to the heart
and symptoms occur because of this damming effect. Most often occurring in the
legs or the arms,
symptoms include:
- swelling,
- warmth,
- redness, and
- pain.
Arterial clots do not allow blood get to the affected
area.
- Pain is the initial symptom of this ischemia, or oxygen deprivation due to
loss of blood supply.
- Other symptoms depend upon the location of the clot, and
often the effect will be a loss of function. Heart attack and stroke are
self-explanatory.
- In an arm or leg, in addition to pain, the limb may appear
white, and weakness, loss of sensation, or
paralysis may occur.
- If
the blood supply is lost to an area of the bowel, in addition to intense pain,
there may be bloody diarrhea.
How are blood clots diagnosed?
The initial step in making the diagnosis of a blood clot is obtaining a
patient history. Since people rarely are able to tell that they have a blood clot, the
health care practitioner will ask questions about what might be occurring.
If a blood clot or thrombus is a consideration, the history may expand to
explore risk factors or situations that might put the patient at risk for forming a
clot.
Venous blood clots often develop slowly with a gradual
onset of swelling, pain, and discoloration. Symptoms of a venous thrombus will
progress over hours.
Arterial thrombi occur as an
acute event. Tissues
need oxygen immediately, and the loss of blood supply creates a situation in
which symptoms begin immediately.
Physical examination can assist in providing additional information that may
increase the suspicion for a blood clot.
- Venous thrombi may cause swelling of an
extremity. It may be red, warm, and tender; sometimes the appearance is
difficult to distinguish from cellulitis or an infection of the extremity. If
there is concern about a pulmonary embolus, the examiner may listen to the
lungs, looking for abnormal sounds caused by an area of inflamed lung tissue.
- Arterial thrombus symptoms are much more dramatic. If a leg or arm is
involved, the tissue may be white because of the lack of blood supply. As well,
it may be cool to touch and there may be loss of sensation and movement. The
patient may be writhing in pain.
Arterial thrombus is also the cause of heart attack (myocardial infarction) and stroke
(cerebrovascular accident) and their associated symptoms.
Testing for venous blood clots
Venous blood clots may be detected in a variety of ways,
though ultrasound is
most commonly used. Occasionally, the patient's size and shape limit the ability
for ultrasound to provide a definitive answer.
Venography is an alternative test to look for a clot. In this test a
radiologist injects
contrast dye into a small vein in the hand or foot and using
fluoroscopy (video
X-ray) and watches the dye fill the veins in the extremity as it travels back to the
heart. The area of clot or obstruction can thus be
visualized.
Sometimes, a blood test is used to screen for blood clots. D-Dimer is a
breakdown product of a blood clot, and its levels in the bloodstream may be
measured. Blood clots are not stagnant; the body tries to dissolve them at the
same time as new clot is being formed. D-Dimer is not specific for a blood clot
in a given area and cannot distinguish a "good” or needed blood clot, one that
forms after surgery or due to bruising from a fall, from one that is causing
medical problems. It is used as a screening test with hopes that the result will
be negative and show that there is no need to look further for blood clots.
Should a blood clot embolize to the lung, this may be a
medical emergency. There are a variety of tests to look for pulmonary emboli. A
plain chest X-ray will not show blood clots, but it may be done to look for
other conditions that can cause chest pain and shortness of breath, which are
the symptoms of a pulmonary embolus. An electrocardiogram (EKG) may show
abnormalities suggestive of a pulmonary embolus and also may reveal other causes
of chest pain.
Computerized tomography (CT scan) is often the test of choice when suspicion of
pulmonary embolus is high. Contrast material is injected intravenously, and the
radiologist can determine whether a clot is present in the pulmonary vessels.
On occasion, a ventilation perfusion (V/Q) scan is
performed to look for pulmonary emboli. This test uses labeled chemicals to
identify inhaled air into the lungs and match it with blood flow in the
arteries. If a mismatch occurs, meaning that there is lung tissue that has good
air entry but no blood flow, it may be indicative of a pulmonary embolus. It is
less accurate that a CT scan and
more subjectective to variances in interpretation.
Testing for arterial blood clots
Arterial thrombosis is an emergency, since tissue cannot
survive long without blood supply before there is irreversible damage. When this
occurs in an arm or leg, often a surgeon is consulted on an emergency basis. Arteriography may be
considered, a test in which contrast material is injected into the artery in
question to look for blockage on imaging studies. Sometimes, if there is a large
artery that is occluded, this test is done in the operating room with the
presumption that a surgical procedure will be needed to open the vessel and
restore blood flow.
For a heart attack (acute myocardial infarction, MI), the EKG may
establish the diagnosis, although blood tests may be used to look for enzymes
(troponin, myoglobin, CPK)
that leak into the bloodstream from irritated heart muscle. In an acute heart
attack, the
diagnostic and therapeutic procedure of choice is a
heart catheterization.
For an acute stroke (cerebrovascular accident, CVA), the test of choice is a
computerized tomography (CT) scan of the head to look for bleeding or tumor as
the cause of stroke symptoms. If the symptoms resolve, the diagnosis is a
transient ischemic attack
(TIA, mini-stroke), and further tests may
include carotid ultrasound to look for blockages in the major arteries of the
neck and echocardiography to
look for blood clots in the heart that may embolize to the brain.
Next: How are blood clots treated? »
- ibuprofen, Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc. - Explains the medication ibuprofen (Advil, Motrin, Nuprin, Medipren) a drug used for the management of mild to moderate pain, fever, and inflammation. Article includes descriptions, uses, drug interactions, and side effects.
- CT Scan (Computerized Axial Tomography) - CT Scan (Computerized Axial Tomography, CAT scan) is a procedure that assists in diagnosing tumors, fractures, bony structures, and infections in the organs and tissues of the body.
- Urinary Tract Infection (UTI In Adults) - Learn about urinary tract infection causes, symptoms, signs, diagnosis and treatment of UTIs in men and women. Antibiotics may be used to treat recurrent bladder infections.
Latest Medical News
Heart RSS