Direct answer. Pressotherapy may help some people feel that their legs are less swollen and lighter when discomfort is linked to venous or lymphatic stagnation, but it does not treat every cause of swelling. “Water retention” is a broad term: persistent, sudden, painful or one-sided swelling should first be assessed so that the cause can be understood.
Key takeaways
- “Water retention” is a common expression; medically, the terms swelling or oedema are more appropriate depending on the situation.
- Ankles and feet may swell after prolonged standing, heat or inactivity, but other causes are possible.
- Pressotherapy applies sequential pneumatic compression: it can be used as a comfort routine, but it is not a universal treatment for oedema.
- Sudden swelling in one leg that is painful, red or hot requires medical advice before any compression.
- More pressure or more sessions does not automatically mean better results.
Water retention, swollen legs and oedema: are they the same thing?
Not exactly. In everyday language, “water retention” often describes a feeling of swelling: ankle marks at the end of the day, tight legs or the impression that tissues have increased in volume. The medical term “oedema” refers to an accumulation of fluid in the tissues.
There are many possible causes. The NHS mentions prolonged inactivity, a very salty diet, pregnancy, certain medicines and varicose veins, but also heart, kidney or liver problems, infection or a blood clot. In other words, two people with swollen legs may have very different causes.
The French national health insurance service also notes that, in venous insufficiency, ankles and feet may swell more at the end of the day and in hot weather. The swelling can improve after a night’s rest.
To understand possible causes and the difference between a simple feeling of swelling and a situation that needs medical advice, see our Eclipse Water Retention guide.
Why can legs swell at the end of the day?
Return circulation depends in part on vein function and on the action of the calf muscles. When we stand for a long time without walking, sit for prolonged periods or remain inactive, this muscle pump works less efficiently. Heat may also encourage veins to dilate and make heavy-feeling legs more noticeable.
| Situation | What you may feel | Useful response |
|---|---|---|
| Prolonged standing | More swollen ankles, heaviness, tightness | Walk regularly and change position |
| Long periods sitting | Numb or swollen legs | Move your ankles and walk as soon as possible |
| Heat | More pronounced swelling and heaviness | Limit prolonged exposure to heat |
| Hormonal changes | A feeling of fluctuating volume | Observe whether it is cyclical and note associated symptoms |
| Sudden or one-sided swelling | One leg clearly more swollen, painful or hot | Have the situation assessed before massage or compression |
How does pressotherapy work on the legs?
Pressotherapy uses air chambers that inflate and deflate according to a programme. This sequential mechanical compression massages the tissues and may support the movement of fluids up the limb.
The same broad principle of intermittent pneumatic compression is studied in certain medical settings, particularly lymphoedema. A systematic review published in 2026 found moderate-certainty evidence that some intermittent pneumatic compression devices reduce volume, oedema or limb circumference in people with chronic lower-limb lymphoedema.
This does not mean that a wellness device treats every form of “water retention”. The trials involve selected populations, specific devices and medically supervised protocols.
For a healthy person mainly looking for comfort after a day spent standing, a more reasonable expectation is simple: a feeling of compression and massage, and possibly legs that feel less tight or less swollen after a session.
Does pressotherapy remove “excess water” and toxins?
It is better to avoid that wording. The body does not store a reservoir of “toxins” that compression boots simply empty. The lymphatic system helps transport fluids and proteins and supports immune function, while the body’s elimination processes also rely on the kidneys, liver, lungs and digestive system.
A change in swelling may temporarily alter how an area feels or looks. That does not mean pressotherapy “detoxifies” the body or causes fat loss.
Focus — less swelling is not the same as weight loss.
Trousers feeling looser after a less swollen day or a compression session does not prove loss of body fat. When tracking progress, always distinguish between the feeling of swelling, circumference and your aesthetic goal.
How many pressotherapy sessions should you do?
There is no scientifically validated universal frequency for “water retention” in the broad sense. Frequency depends on the device, goal, tolerance and medical context.
For a wellness routine with an Eclipse device, 3 to 5 sessions per week of 20 to 30 minutes can be a practical reference point to adjust according to comfort and the instructions. Daily use is neither essential nor automatically more effective.
For more detail, see our guide How often should you use pressotherapy, and can you use it every day?.
What pressure should you choose when your legs are swollen?
The pressure should remain comfortable. Higher pressure is not proof of better effectiveness. Reviews of pneumatic compression in lymphoedema also show that the protocols studied use very different pressures and durations: there is no single value suitable for everyone.
Start gradually. Stop if you experience sharp pain, persistent numbness, a cold or pale foot, or an unusual change in skin colour.
Our guide to pressotherapy pressure and programmes explains settings without turning the device’s maximum pressure into a target.
When should you not try to “drain” swelling yourself?
New, sudden or unexplained swelling should be understood before it is massaged or compressed. The French national health insurance service notes that deep vein thrombosis may involve pain, heaviness in the calf and swelling. The NHS also recommends urgent assessment when swelling in one leg develops suddenly or becomes painful, red or hot.
Shortness of breath, chest pain, faintness or coughing up blood require urgent medical attention.
Before a session, also read our pressotherapy contraindications and precautions.
Boots or trousers: which device is best for a comfort routine?
The choice mainly depends on the area you want to cover. If your discomfort is mainly in the feet, ankles, calves and legs, boots are the most direct format. If you want higher coverage including the thighs, hips and lower abdomen, trousers are more suitable.
For a first set-up focused on the legs, the Eclipse 8C Complete Compression Boots Set includes the boots and control unit required to get started.
Not sure whether to choose 8C, 12C PRO, boots or trousers? Compare coverage and technologies on Our Devices.
FAQ: pressotherapy and water retention
Can pressotherapy make swollen legs feel less puffy?
It may help some people feel that their legs are less tight or less swollen, particularly as part of a comfort routine. Persistent swelling or swelling related to a medical condition should, however, be assessed and managed according to its cause.
Does pressotherapy make you lose water or weight?
A temporary change in fluid or swelling may alter the circumference of an area, but that is not the same as losing body fat. Pressotherapy should not be presented as a weight-loss method.
Can you use pressotherapy if your ankles are swollen?
Mild swelling in both ankles after a day spent standing does not mean the same thing as sudden swelling in one ankle. If swelling is new, significant, painful, red, hot or unexplained, seek advice before using compression.
Does pressotherapy replace manual lymphatic drainage?
No. Pressotherapy provides programmed pneumatic compression, while manual drainage relies on a hands-on technique adapted by a professional. The two are not automatically interchangeable.
Should you use maximum pressure to improve drainage?
No. A device’s maximum pressure is a technical capability, not an instruction. A session should remain comfortable and progressive.
Sources and transparency
Transparency: Eclipse sells pressotherapy devices for wellness use. The medical pneumatic-compression studies cited here help explain mechanisms and limitations; they do not constitute specific clinical evidence for Eclipse devices.
- Assurance Maladie — Jambes lourdes : symptômes, causes et facteurs favorisants, 2026.
- NHS — Swollen ankles, feet and legs (oedema).
- O’Donnell TF Jr et al. — Systematic review of intermittent pneumatic compression for lower-extremity lymphedema, 2026.
- Phillips JJ, Gordon SJ — Intermittent pneumatic compression dosage for lymphedema: systematic review.
- Assurance Maladie — Phlébite : symptômes et diagnostic, 2026.
