How much compression?

The pressure a stocking exerts is measured at the ankle in millimetres of mercury (mm Hg). Different compression ranges result from varying the knit design and elastomeric yarn type and denier.

Compression hosiery in the UK could be classified in four groups:

1. Support Hosiery

These garments generally provide an ankle pressure of less than 14mm Hg at the ankle. The packs are usually marked with the relevant compression value at the ankle, the higher the compression value the stronger the stocking.

2. Anti-Embolism Stockings

These stockings were for the prevention of Deep Vein Thrombosis (DVT) whilst patients are in bed in hospital. They provide a pressure at the ankle of between 15-20 mm Hg. The garments are normally white in colour with an open or inspection toe.

3. Stockings Conforming to RAL-GZ 387

This specification originated in Germany and is the basis for all compression hosiery recognised by the Health Insurance Schemes in both Germany and Switzerland. For more than 30 years stockings of this type have been prescribed for their patients by Vascular Consultants in hospitals in the UK.

The Compression Classes and the indications for use are:

COMPRESSION CLASS	PRESSURE AT THE ANKLE IN mm Hg*	INDICATIONS FOR USE
I	18 - 21	Slight varicosity Oedema. Varicose vein prevention during pregnancy.
II	23 - 32	Pronounced varicosis Pronounced oedema Following sclerotherapy and varicose vein surgery Varicose veins during pregnancy Chronic venous insufficiency Prevention of leg ulcers
III	34 - 46	Severe varices with oedema Following sclerotherapy and varicose vein surgery Prevention of leg ulcer recurrence Severe Chronic venous insufficiency (CVI) Mild lymphoedema
IV	49 and higher	Severe lymphoedema
* Millimetres of Mercury

4. Stockings Conforming to UK Drug Tariff Specification 40

COMPRESSION CLASS	PRESSURE AT THE ANKLE IN mm Hg*	INDICATIONS FOR USE
1	14-17	Superficial or early varicose veins Varicose veins during pregnancy
2	18 -24	Varicose veins of medium severity Venous ulcer treatment and prevention of recurrence Mild leg swelling Varicose veins during pregnancy
3	25-35	Gross varicose veins Severe venous insufficiency Gross leg swelling Venous ulcer treatment and prevention of recurrence
* Millimetres of Mercury

5. Contra-Indications Warnings and Precautions

Care should be taken to observe specific manufacturers contra indications warnings and precautions. In general these may include:

Absolute contra-indications:

- Arterial disease in the legs.
- Severe heart disease.
- Severe infections of the veins.

Relative contra-indications:

- Infections of the skin.
- Loss of feeling in the legs.
- Allergy to compression stocking fabric.

Further information is available in our Credalast Instructions for use leaflet:

Click here to download PDF Credalast Instructions for use Click here to view online

The information on this site has been designed to show best practice and to guide with the latest advice. However, information contained on this site represents our views and is not meant to be a substitute for consultation with Health Care professionals.