Deep vein thrombosis (DVT)

What is deep vein thrombosis (DVT)?

Deep vein thrombosis (DVT) is a blood clot that occurs in a deep vein.

DVT is most often seen in the leg but can occur elsewhere in your body, such as your arms or abdomen.

What are the symptoms of DVT?

The main signs and symptoms of DVT are pain and swelling in the affected area — usually your calf or thigh. The area may:

• feel tender
• look red

Some people have no signs or symptoms. This is called a silent DVT.

What causes DVT?

Anything that slows blood flow in deep veins can cause DVT. One of the most common risk factors is being immobile (not moving) for many hours.

Factors that can increase your risk of having DVT are:

• having an injury such as a bone fracture
• being in hospital for surgery or a major illness
• sitting still for a long time, such as during a long-haul flight
• having conditions such as cancer or heart failure
• taking treatments such as the oral contraceptive pill (‘the pill’) or hormone replacement therapy that contain the hormone oestrogen
• being pregnant
• having a genetic condition that makes your blood more likely to clot

Lifestyle factors that can increase your risk include:

• being overweight
• smoking

DVT can also happen suddenly, with no obvious cause.

When should I see my doctor?

DVT is a serious condition. If you think you may have DVT, you should see your doctor straight away.

Call an ambulance on triple zero (000) if you:

• become short of breath
• have pain in your chest
• have a rapid pulse
• feel dizzy or faint
• cough up blood

How is DVT diagnosed?

Your doctor will ask about your symptoms and examine you.

A blood test called a D-dimer test can be done to help detect blood clots.

If your doctor thinks you may have DVT, they may send you for an ultrasound scan or another type of scan.

How is DVT treated?

The exact treatment for DVT depends on the location of the clot and your risk of complications.

If you have DVT, you will probably be treated with an anticoagulant (blood thinner) medicine. This will reduce further blood clotting.

You might take tablets or have injections. You may need to take anticoagulant medicine for several months, or even longer.

You may also need to wear compression stockings.

In rare cases, you may need a different type of medicine called a thrombolytic. This is used to dissolve and break down the blood clot.

How can DVT be prevented?

There are some steps you can take to help prevent DVTs.

If you are travelling for hours (for example, on planes or trains), remember to:

• get up to walk around every hour or 2
• do exercises like calf stretches or heel lifts
• drink plenty of water
• avoid alcohol or caffeine as these can add to dehydration
• wear compression stockings if you have other DVT risk factors

When in hospital or recovering from illness, make sure that you:

• tell hospital staff if you have had DVT before
• wear compression stockings
• move your feet and legs when possible, even if you are unable to walk around
• stay hydrated

If you have had DVT before, do your best to:

• quit smoking
• keep fit
• maintain a healthy weight

Complications of DVT

Part of the blood clot can break off and travel to the lungs. This is called a pulmonary embolism and is a dangerous condition. Symptoms of a pulmonary embolism include chest pain and shortness of breath.

After having DVT, your leg can stay swollen for a while. You may find that your skin becomes discoloured or itchy.

It’s common to have complications after DVT. See your doctor if you are concerned.