The combined letters mmHg is a medical/physiological acronym that stands for millimeters of mercury which is an international standard unit of measurement used to classify the amount of pressure or level that is provided by different types of gradient and non-gradient compression hosiery, e.g. compression socks, compression stockings, and TED hose.
Broken down, mm stands for millimeters of mercury (unit of pressure) and Hg is the chemical symbol for mercury. The higher the number the stronger the compression.
Garment compression levels depending on the type of compression garment can range from 8 mmHg and the way up to 60 mmHg.
All compression garment strengths are measured starting at the ankle to the top of the garment. There is no national standard for the range of compression levels, however, the [ranges] stated by different manufacturers are generally within plus or minus 5% of one another.
Various mmHg compression levels
Below is a breakdown of the range of compression levels and the conditions they are best suited to treat. (NOTE: these measurement ranges and what they are intended to treat can vary from manufacturer to manufacturer).
8 mmHg (Extra light)
All garment products with this compression value, or less, may be worn for the following reasons:
- Accommodate swelling in the feet, ankle and lower leg (ex. diabetic socks)
- Fatigued calf muscles
9-17 mmHg (Light)
Garments within this range may be worn to prevent and or treat the following conditions:
- Moderate swelling (edema)
- Prophylaxis (the measures taken in order to prevent problems) during pregnancy
- Heavy, fatigued, aching calf muscles (ex. support socks and compression stockings)
18-24 mmHg (Moderate)
Foot and leg garments within this range may be worn to prevent and or treat the following conditions:
- Heavy, fatigued, aching calf muscles
- Medium to severe varicose vein
- Spider veins
- Minor Leg ulcers
- Early stages of DVT
- Heavy edema
25-30 mmHg (Firm)
Products within this category may be of use in preventing and or treating the following:
- Severe Varicose Vein
- DVT in advanced stages
- Severe edema
35-60 mmHg (Extra firm)
Products within this category should be used with great care as the compression level is very high. However under proper medical supervision the products may be used in Preventing and or treating the following:
- Severe Varicose Vein
- DVT in advanced stages
- Severe Lymphoedema
- Elephantitis
