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DVT (deep vein thrombosis)

DVT (deep vein thrombosis) is a blood clot in a vein, usually in the leg. DVT can be dangerous. Get medical help as soon as possible if you think you have DVT.

Symptoms of DVT (deep vein thrombosis)

Symptoms of DVT (deep vein thrombosis) in the leg include:

  • throbbing pain in 1 leg (rarely both legs), usually in the calf or thigh
  • swelling in 1 leg (rarely both legs)
  • red, blue or darkened skin around the painful area – this may be harder to see on brown or black skin
  • swollen veins

These symptoms can sometimes happen in your arm if that's where the blood clot is.

Sometimes the only symptom you may have is pain in your lower tummy. This is a symptom of pelvic vein thrombosis, but this is rare.

Urgent advice: Ask for an urgent GP appointment or get help from NHS 111 if:

  • you think you have DVT (deep vein thrombosis)

You can call 111 or get help from 111 online.

If you're pregnant you can also call an early pregnancy unit (if you're less than 20 weeks) or your maternity unit, if you have the phone number.

Immediate action required: Call 999 or go to A&E if:

You have symptoms of DVT (deep vein thrombosis), such as pain and swelling, and:

  • feel short of breath
  • have chest pain

DVT can be very serious because blood clots can travel to your lungs. This is called a pulmonary embolism.

A pulmonary embolism can be life-threatening and needs treatment straight away.

Information:

Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance.

Bring any medicines you take with you.

Who is more likely to get DVT (deep vein thrombosis)

A DVT (deep vein thrombosis) is more likely to happen if you:

  • are aged over 60
  • are living with overweight or obesity
  • smoke
  • have had DVT before
  • take HRT
  • take the combined contraceptive pill or use contraception that contains oestrogen, such as the patch or vaginal ring
  • have cancer or heart failure
  • have varicose veins
  • have inflammatory bowel disease or vasculitis

There are also some times when you have a higher chance of getting DVT.

These include when you:

  • are staying in or recently left hospital – especially if you cannot move around much
  • are having, or have had, surgery
  • are confined to bed for 3 days or more
  • go on a long journey (more than 4 hours) by plane, car or train
  • are pregnant or if you've had a baby in the previous 6 weeks
  • are pregnant and have had DVT before
  • are dehydrated

Sometimes DVT can happen for no obvious reason.

How DVT (deep vein thrombosis) is diagnosed

If a doctor thinks you have DVT (deep vein thrombosis), you should be referred to hospital within 24 hours for an ultrasound scan.

The scan shows whether blood is flowing normally through the vein.

Treatment of DVT (deep vein thrombosis)

DVT (deep vein thrombosis) is treated with blood-thinning medicines.

You'll usually need to take blood-thinning medicines, such as rivaroxaban, for at least 3 months to reduce your risk of getting another blood clot. These medicines are usually taken as tablets.

If you get a DVT when you're pregnant, you'll usually need blood-thinning injections for the rest of your pregnancy and until your baby is 6 weeks old.

Recovery from DVT (deep vein thrombosis)

There are things you can do to help you recover from DVT (deep vein thrombosis).

After you leave hospital, you'll be encouraged to:

  • stay active – walk regularly if you can
  • keep your affected leg raised when you're sitting
  • delay any flights or long journeys until at least 2 weeks after you start taking blood-thinning medicine

How to prevent DVT (deep vein thrombosis)

There are things you can do to lower your chance of getting DVT (deep vein thrombosis).

Do

  • stay a healthy weight

  • stay active – taking regular walks can help

  • drink plenty of fluids to avoid dehydration – DVT is more likely if you're dehydrated

Don't

  • do not sit still for long periods of time – get up and move around every hour or so

  • do not smoke

  • do not drink lots of alcohol

Going on a long journey

If you're travelling for 4 hours or more by plane, train or car, there are things you can do during the journey to lower your chances of getting DVT.

These include:

  • wearing loose clothing
  • drinking plenty of water
  • avoiding alcohol
  • walking around when possible

Going into hospital

If you go into hospital, your healthcare team should check if there's a higher chance you'll get DVT.

If they think you're more likely to get DVT, you may be given treatment to prevent it, such as medicine. You may also be given compression stockings (knee-high elastic socks that help your blood circulation) while you're in hospital.

Sometimes you may continue treatment to prevent DVT after you leave hospital, for example, if you've had surgery, because a blood clot can happen weeks later.

You can also help reduce your risk of DVT while you're in hospital by staying active and walking around if you can.

Page last reviewed: 30 April 2026
Next review due: 30 April 2029