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What causes varicose veins

Varicose veins are usually caused by weak vein walls and vein valves.

There are one way valves inside your veins which open to allow blood through and then close to prevent blood from flowing downwards.

Sometimes due to excessive pressure and strain on the veins, the walls of veins become stretched and the walls then lose elasticity causing weakening of the valves.

Sometimes in dilated , distended veins, valves are not able to appose to each other causing \ incompetence.

If the valves don't function properly, this can cause the blood to leak and flow backwards. If this happens, the blood collects in your veins, which become swollen and enlarged to accommodate the blood.

The reasons why the walls of the veins stretch and the valves in your veins weaken aren't fully understood in many patients. Some people develop the condition for no obvious or apparent reason.

Increased risk

A number of things can increase your likelihood of developing varicose veins, including:

· being female

· having a close family member with varicose veins

· older age

· being overweight

· having a job that involves long periods of standing or long periods of sitting

· being pregnant

· other conditions


Women are more likely to be affected by varicose veins than men. Research suggests this may be because female hormones tend to relax the walls of veins, making the valves more prone to leaking.


Your risk of developing varicose veins is increased if a close family member has the condition.

This suggests varicose veins may be partly caused by your genes (the units of genetic material you inherit from your parents).


Aging. As you get older, your veins start to lose their elasticity and the valves inside them stop working well.

Being overweight

Being overweight puts extra pressure on your veins, which means they have to work harder to send the blood back to your heart.

This can put increased pressure on the valves, making them more prone to leaking.

The impact of body weight on the development of varicose veins appears to be more significant in women.


Some research suggests jobs that require long periods of standing may increase your risk of getting varicose veins.

This is because your blood doesn't flow as easily when you're standing for long periods of time.


During pregnancy, the amount of blood increases to help support the developing baby. This along with compression of the pelvic veins by the womb puts extra strain on your veins.

Increased hormone levels during pregnancy also cause the muscular walls of the blood vessels to relax, which also increases your risk.

Although being pregnant can increase your risk of developing varicose veins, most women find their veins significantly improve after the baby is born.

Other conditions

In rare cases, varicose veins are caused by other conditions.

These include:

- a previous blood clot

- a swelling or tumour in the pelvis

- abnormal blood vessel


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