Varicose veins are swollen veins that
appear lumpy and blue through the skin.
Any vein in your body
can become varicose
but the veins in the legs, particularly
the calf, are most commonly affected.
Varicose veins are a common condition,
affecting both men and women.
So what causes varicose veins?
Blood travels around your body
through blood vessels.
Arteries carry blood from the heart
to the rest of the body
and veins return blood to the heart.
When your leg muscles move, they squeeze the leg veins
and help to push the blood upwards to your heart.
Inside the large veins of your body are one-way valves
which stop blood flowing backwards in the wrong direction.
In varicose veins the walls of the veins stretch and become less flexible,
which weakens the valves and stops them from working properly.
Blood then leaks backwards and builds up in the vein, causing it to swell.
The reason why your veins and valves stretch and stop working
is not fully understood.
But common risk factors are obesity, having an occupation
that involves standing a lot and pregnancy.