By Jennifer Bradley, Staff Writer
Watch out, brothers and sisters—if a sibling has
experienced blood clots, you may have a 50-fold
increase in risk for the condition.
Researchers in Sweden are the first to link
venous thromboembolism (VTE) and the risk in other
family members in a nationwide setting, sorted by
age and gender. They used a nationwide
hospitalization registry to explore the influence of
sibling history on these dangerous blood clots. This
is a quick look at VTE, the sibling connection and
some preventive tips for people of all ages.
What is VTE?
VTE consists of deep vein thrombosis (DVT), which
occurs when blood clots form in the deep veins of
legs or pelvis. VTE also encompasses pulmonary
embolism, which is when the blood clot breaks away
from the original location, travels to the lungs and
blocks pulmonary arteries, becoming deadly.
It is the third most common cardiovascular
illness, after stroke and heart attack, and affects
one in 1,000 people every year. One-third of VTE
cases also involve a pulmonary embolism.
There are three main factors necessary to
maintain the correct thickness and flow of blood in
the vessels. When one of these is disrupted, a blood
clot is likely to occur.
The flow of blood – When blood flow within the
veins is slowed or blocked, this allows more time
for the blood to clot.
The vessel wall – The blood vessel wall lining
must be intact. Damage to the wall (for example,
from surgery or injury) hinders the flow of blood
and may lead to the formation of a blood clot.
Blood composition – The body maintains an
effective balance between processes that dissolve
and form blood clots. If this balance is disturbed
and there are too many blood-clotting factors
present, this increases the tendency of the blood to
The Sibling Connection
Depending on the number of children in a given
family with the disorder, the risk is that much
greater for other siblings. If one sibling has VTE,
the risk is two times greater, but 50 times greater
when two or more brothers or sisters have the same.