The Centers for Disease Control and Prevention
estimates that there are 300,000 to 600,000 VTE events
annually in the United States.
VTE is an equal opportunity condition and can affect
people of either gender, all ages, races and ethnicities.
But some risk factors for VTE are stronger than others.
Increasing age (from 40 on) means increased risk.
Experiencing surgery, major trauma, fractures of the hip
or leg, also carries strong risk. Other independent risk
• Active cancers and chemotherapy
• Prior superficial vein thrombosis
• Varicose veins
• Inherited thrombophilia (a condition that tends to
make the blood clot more easily)
• Kidney disease
• Prolonged immobility such as hospital or nursing
home confinement or leg paralysis due to, for example,
stroke or spinal cord injury
And among women:
• Use of oral contraceptives
• Pregnancy/postpartum period
• Hormone therapy
Any of the factors below alone may not justify preventive
measures for VTE, but a combination of two or more may
be cause for action and may have an effect on the length and
type of treatment someone receives:
Prior VTE — People who have had a previous episode
of VTE have a high risk of recurrence. In one study,
patients with a history of VTE were eight times more
likely to develop a new episode during a high-risk period,
such as surgery or serious illness, than patients without
such a history.
Age — Patients older than 40 are at higher risk, and that
risk doubles with each subsequent decade.
Cardiac or respiratory failure
Immobility — Prolonged immobility like on very long
flights combined with other major risk factors increases
the chances of VTE.
Oral contraceptives — Women who use estrogens
for contraception or menopause and men receiving
estrogen therapy for prostate cancer are at increased risk
Some inherited or acquired blood conditions,
such antiphospholipid antibody syndrome.
Being pregnant, or having had a baby recently
puts a woman at greater risk of developing a blood clot.
Her risks increase when the following also apply:
• Has experienced previous blood clots
• Genetic predisposition to blood clots
• Prolonged immobility, such as bedrest or long
• Multiple births
• Increased maternal age
• Other illness, such as cancer and serious infection
Diagnosis is done by assessment — a healthcare
professional gathers information about a person’s medical
history, age, medications and specific lifestyle factors.
A Doppler ultrasound may be performed on the legs and
certain blood tests that detect a greater chance of blood
clotting may be performed. Additional testing with CT
angiography (a test used to see arteries and veins throughout
the body) may be done if PE is suspected.
Those determined at risk of VTE based on medical
assessment may receive treatment designed to prevent
clots from forming. This treatment may include
approaches such as:
VTE is an equal
can affect people
of either gender, all
ages, races and