Deep vein thrombosis (DVT)

Deep vein thrombosis (DVT):

A Bad Clot

Long plane journeys can put you at risk of deep vein thrombosis. - AFP

Beware blood clots in the deep veins of the body.

I RECENTLY went for a charity walk to raise awareness about deep vein thrombosis. I learned that office workers who don’t exercise or move around a lot are at risk of getting this condition. What is deep vein thrombosis?

Deep vein thrombosis (DVT) occurs when a blood clot forms in one or more of the deep veins in your body. This usually happens in your legs, thighs or pelvis when your blood becomes thicker.

It is true that DVT happens when you don’t move for a long time, like if you are confined to bed after a fracture or major surgery, or after you have a stroke.

Is it a common problem? I have never heard of it before this.

It is quite common, but perhaps not as common as heart attacks or strokes. In the US, 300,000 to 600,000 people get it every year.

It can be quite dangerous because the blood clot (thrombus) can break off and travel through your bloodstream. Once the thrombus has broken off, it is called an embolus.

An embolus can travel to your lung arteries and block the blood flow there. This serious condition is called pulmonary embolism. If not treated, pulmonary embolism can lead to death.

Blood clots which form in your thighs are more likely to break off and cause pulmonary embolism than the ones in your lower legs or other parts of the body.

Why do some people get it and others don’t? I work in an office and I don’t have it.

There are several factors which put you at higher risk:

-Blood clots are more likely to form when your vein’s inner lining is damaged. This damage can be caused by injuries or surgery, or even immune responses to infections or chemicals.

- If your blood flow is sluggish or slow, blood clots are also more likely to be produced. Your circulation can get really slow after you are immobilised, such as when you are recovering after surgery or if you have been ill.

This can also happen if you are sitting for a long time, such as in a plane or at the office. So it is always advisable that you take a walk around the plane or office every so often.

- If you have thicker blood than normal, such as if you have certain clotting factor conditions.

- If you take oral contraceptives or hormone therapy.

- If you are pregnant or in the six weeks after you have given birth.

- If you are on treatment for cancer.

- If you are obese.

- If you smoke.

How will I know if I have DVT?

You might not know it! Only 50% of people who have DVT know they have DVT.

Other than not producing symptoms, DVT can cause pain in your leg, which you may only experience if you are standing or walking. There may be some tenderness in the area, or even swelling of your leg or along the vein.

There may be increased warmth in the area of your leg which is swollen or painful. The skin may be red or discoloured.

Sometimes, DVT may present itself as a pulmonary embolism, in which you have a sudden unexplained shortness of breath or pain during deep breathing. You may also cough up blood.

You have to go to the hospital immediately if you get symptoms like these.

Can DVT be treated?

Yes. The doctor has to stop the blood clot from getting bigger, prevent it from breaking off and becoming an embolus, and reduce your chances of getting another blood clot.

This can be done by giving you anticoagulants such as warfarin or heparin. These are also known as blood thinners and will decrease the blood’s ability to clot.

Please note than these cannot break up your blood clots which have already formed. But your body can dissolve most blood clots with time.

You usually have to be treated for six months.

The doctor can also give you thrombolytics, which are medicines that can dissolve large clots. These can cause sudden bleeding, so they are given with care and in life-threatening situations, like pulmonary embolism.

I am going on a long plane journey to the US. How can I minimise the risk of DVT?

There is actually a low risk of developing DVT while you are travelling unless you have a pre-existing condition.

But the risk increases if the flight time is four hours or more.

You can walk up and down the aisle of the plane. When you sit down, you can move your legs and flex or stretch your feet to improve blood circulation in your calves.

Wear loose and comfortable clothing, and drink lots of water and avoid drinking alcohol.

About Dr YLM

 Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, e-mail starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.