Compression levels and indications
Basically, the greater the compression level, or compression strength, the tighter the compression stocking. These levels are measured in millimeters of mercury (mmHg). It's the same scale used to take your blood pressure.
The most beneficial compression socks are “graduated” as opposed to “uniform” in strength. Graduated compression socks are tighter at the ankle than they are at the top. The graduation helps push blood back up toward the heart, aiding in circulation.
Compression stockings with relatively low compression levels can be purchased without a prescription at drugstores, medical supply stores, and online.
These over-the-counter items usually come in compression levels of around 15-20 mmHg.
Compression stockings with higher levels of compression are prescribed by doctors. The prescription will include the specific strength you need. By law, no prescription is required, but most pharmacies won’t dispense higher-level compression wear without a prescription.
By “high-level compression,” we mean those that generally range from 20-30 mmHg to 30-40 mmHg; while these strengths are generally safe to wear, certain individuals may be at risk of harm due to contraindications, so the oversight of a doctor is always recommended. Compression levels in even higher ranges do exist, but your doctor should tell you about those.
A trained and certified fitter will need to take measurements to ensure you get the correct level of compression and size. If your doctor or physical therapist can’t do the fitting, they should be able to refer you to someone who can.
Compression levels explained
What medical issues are the various compression levels used for? Here’s a guide. These are general guidelines. The severity of a certain issue will help determine the level needed.
As mentioned, you should talk to your doctor about which compression level is right for you.
8-15 mmHg
- Mildly aching and tired legs
- Support and comfort for either standing or sitting for long periods
- When just a little support is needed for general health and energy
15-20 mmHg
- Slightly more support, offering day-to-day relief from achy, heavy, slightly swollen legs
- Extra support on busy, active days, or when traveling
- An aid for enhanced circulation, especially in the legs
- During pregnancy, they can help prevent varicose and spider veins
20-30 mmHg
- The most commonly prescribed compression level by doctors
- Used to help a variety of minor to moderate medical conditions
- Used to help chronically painful, heavily fatigued legs
- Helpful in the treatment of varicose veins
- Relief from the swelling associated with mild edema
- Used in combination with elective surgical procedures such as sclerotherapy and phlebectomy
- Used to help treat orthostatic/postural hypotension, a form of low blood pressure
30-40 mmHg
- Relief from moderate and severe edema and lymphedema
- Helps prevent and relieve more serious cases of varicose veins
- Used in the treatment of deep vein thrombosis (DVT) and post thrombotic syndrome
- Can help heal active venous stasis ulcers
- Used after bone fractures and orthopedic surgeries
- Used to treat phlebitis
- Used in treating skin changes with healed ulceration
40-50 mmHg
- Used as part of the treatment for chronic venous insufficiency
- Used for the most severe cases of DVT and post thrombotic syndrome
- Used in treating severe skin changes with active ulceration
Determining the right size for the lower-strength compression stockings you can purchase without a physician:
You can use our sizing wizard to easily find your size online. You can then use that information to make your purchase at a local store or online.
Shoe size is usually a factor in the sizing of compression stockings, as well as measurements of the ankle and calf. When measuring the ankle, measure at the thinnest point. For calf measurements, measure at the thickest point. For calf length, measure from the floor to the right-angle bend of the knee (in sitting position). It’s also best to take measurements as soon as possible after waking in the morning, when swelling is at a minimum.
When should I consider using compression stockings, or see a doctor for their recommendations?
- Legs that are chronically swollen, painful, or fatigued
- Poor blood flow in the legs
- A known risk for blood clots, especially in the legs
- A history/family history of deep vein thrombosis
- Long bed rests, for example after surgery
- Varicose veins or venous leg ulcers
Compression stockings are often used to relieve a minor issue, before it turns into a major one.
What existing health issues could mean that compression stockings are not right for me?
- Arterial insufficiency, intermittent claudication, ischemia
- Uncontrolled congestive heart failure (CHF)
- Acute dermatitis, weeping dermatosis, cutaneous sepsis
- Signs of infection in the legs
- There may be others. Be sure your physician is familiar with your medical history before they prescribe compression socks.
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
What is compression therapy?
CEAP classification for chronic venous disorders
