What are compression levels and when is each used?

The basic rule is that the higher the compression level or compression strength, the tighter the compression stocking. The pressure is stated in millimetres of mercury (mmHg). This is the same scale used to measure blood pressure.

Legs and feet of a person climbing stairs

The compression stockings with the largest benefit have graded compression strength, in contrast to ungraded stockings. Graded compression stockings are narrower at the ankle than the top. The grading helps to pump the blood back towards the heart and thus supports the circulation.

Compression stockings with relatively lower compression levels, as well as support stockings, can be purchased without prescription in drug stores, healthcare supply stores and online.

These prescription-free items are usually available in compression levels of around 15–20 mmHg.

Compression stockings with higher compression levels are prescribed by doctors. The prescription indicates the specific strength you require. No prescription is required according to law, but most pharmacies will not dispense compression clothing with higher compression levels without a prescription.

Higher compression levels indicate strengths ranging from 20–30 mmHg to 30–40 mmHg. Although these strengths are generally safe to wear, there is a risk for some persons that they may be injured owing to contraindications. It is therefore always recommended to consult a doctor. There are compression levels in even higher ranges; however, please consult a doctor regarding these.

A medical specialist must measure you to ensure you receive the correct compression and size. If your doctor cannot perform the fitting, you should be referred to someone who can.

For what medical problems are the different compression levels used? A broad overview is provided below.

These are general guidelines. The severity of a problem helps to determine the level required.

As mentioned above, you should consult your doctor regarding the compression level appropriate for you.

Compression level 1

18–21 mmHg

  • Mildly painful, heavy and tired legs
  • Support and comfort when standing or sitting for long periods
  • Support for general health and energy
  • For improved circulation, especially in the legs
  • Additional support on active days when you work hard or take a trip
  • These products may help during pregnancy to prevent varicose veins and reticular veins

Compression level 2

23–32 mmHg; the most frequent compression level prescribed by doctors

  • For varicose veins with mild tendency to oedema
  • For varicose veins during pregnancy
  • After a varicose vein treatment with surgery such as sclerotherapy and phlebectomy
  • For the treatment of orthostatic/postural hypotension, a form of low blood pressure
  • For deep vein thrombosis
  • For post-thrombotic syndrome
  • For healed leg ulcers

Compression level 3

34–46 mmHg

  • For moderate venous oedema and lymphoedema
  • For lipoedema
  • Used after broken bones and orthopaedic operations
  • Used for the treatment of skin changes with healed ulcers

Compression level 4

at least 49 mmHg

  • For severe lymphoedema
  • For pronounced post-thrombotic syndrome

When should I consider wearing compression stockings and consult a doctor?

  • Pregnancy
  • Chronically swollen, painful or tired legs
  • Poor circulation in the legs
  • Varicose veins or venous leg ulcers
  • A known risk of blood clots, especially in the legs
  • History or family history of deep vein thrombosis
  • Long confinement to bed, for example after an operation
  • Prevention: It makes good sense to wear compression stockings to fix a small problem before it becomes a big one.

When is caution required with compression stockings?

  • Arterial insufficiency, intermittent claudication, ischaemia
  • Uncontrolled congestive heart failure (CHF)
  • Acute dermatitis, weeping dermatosis, cutaneous sepsis
  • Signs of an infection in the legs

There may also be other reasons. Make sure that your doctor is aware of your medical history before they prescribe compression stockings.

What is the difference between compression stockings and support stockings?

The term “support stockings” is widely known and often also used for medical compression wear. The principles of the two types of stockings are different, though.

Support stockings exert passive resistance to swelling, while compression stockings apply active pressure on the veins of the leg. This prevents them from dilating and facilitates venous return.

Medical compression garments are produced under strict medical and technical specifications to guarantee adequate ankle pressure and graduated compression along the leg. 

Further reading