Clot prevention post leg injury / cast

Cork Emergency Departments

Print Version

What is a DVT?

A Deep Vein Thrombosis (DVT) is a blood clot in a vein, which is commonly found in the leg. When it occurs it may cause pain, redness, tenderness and swelling around the site of the clot. If it travels to your lungs (Pulmonary Embolism, PE) it causes chest pain, shortness of breath and it can cause you to collapse.

What is my risk of a DVT?

The chance of a healthy adult developing a clot in their leg is about 1/1000. After an injury requiring immobilisation in a cast or boot this risk increases to 1/100.

Do I need treatment to prevent a clot?

The Emergency Medicine team looking after you will ask you some questions to assess whether you may benefit from blood thinner treatment while you are wearing your cast or boot.

What is the treatment required?

Blood thinner tablets or injections, in general, are advised as the first line of protection against clots: usually Rivaroxaban or a similar drug.

Print Version.

Let your doctor know if:

Are there side effects from blood thinners?

Most commonly:

  • Spontaneous bruising
  • Bleeding from wounds which can take longer to stop than normal
  • Pain, itch, bruising or bleeding, redness, swelling, nodules or hard lumps, under your skin where the injection was given


  • Allergic reaction
  • Significant internal bleeding

Seek medical advice if you develop:

Can I still develop a clot?

If you develop worsening:

Despite appropriate treatment for your injury you should seek further medical assessment. If you were to develop a clot despite these preventative measures your blood thinner would need to be increased in both dose and duration.

Content modified from by Dr Íomhar O'Sullivan on 30/04/2024.

If you are concerned, please contact the Emergency Department you first attended:

Mercy Injury Unit, Gurranabraher (021)4926900

LIU Mallow(022)58506

LIU Bantry(027)52900

Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 05/01/2024.

Print Version