Water Retention (Oedema): Causes, Medications & What Helps
By the evening your shoes no longer fit, your ankles are swollen, and your ring is leaving a mark: water retention — medically known as oedema — is not just a cosmetic issue. It can point to medication side effects, heart problems, or vein disease. At the same time, there are medications that are specifically prescribed to treat oedema — and others that cause it in the first place. Here you will find out how to assess water retention, what role medications play, and when you need to take action.
Sudden one-sided leg swelling with pain and redness — seek medical help immediately. Possible DVT!
1. What You Can Do Right Now
Quick relief for swollen legs
Elevate: Raise your legs above heart level — swelling often subsides within 30 minutes.
Move: Stand up, circle your feet, take a short walk. The calf muscle pump pushes fluid back into the venous system.
Cool: Run cold water over your lower legs.
Drink: Staying well hydrated helps the body excrete water — counterintuitive but true.
Review your medications: Are you taking amlodipine, prednisolone, or painkillers? These are among the most common causes.
EMERGENCY: Sudden one-sided leg swelling!
Sudden, one-sided swelling of one leg with pain and warmth — call 999 or go to A&E immediately. This could be a DVT (deep vein thrombosis)!
2. Understanding Water Retention — What Happens in the Body?
Oedema develops when fluid leaks from blood vessels into the surrounding tissue and is not adequately drained away. Swelling typically appears in the lowest points of the body — ankles, feet, and lower legs are most commonly affected. A typical sign: if you press a finger into the swelling, an indent remains (known as "pitting oedema").
Simple self-test: weigh yourself daily
A weight gain of more than 2 kg (around 4.5 lb) in 2–3 days without any change in diet suggests fluid retention. This is particularly important in heart failure — for more, see the article on torasemide.
3. Common Causes of Water Retention
3.1 Medications — an underestimated cause
Several commonly prescribed medications can cause or worsen oedema — and at the same time, there are medications specifically used to treat it:
Treats oedema — excretes excess water via the kidneys. Take in the morning!
Table scrollable to the right
Important: raise amlodipine-related oedema with your doctor
Ankle oedema caused by amlodipine is common and bothersome — but diuretics won't help. The doctor may need to switch to a different active substance. Check your medication with the brite interaction check.
3.2 Prolonged standing or sitting
Gravity and a lack of calf muscle activity: anyone standing or sitting for hours (office work, long-haul flights) often notices swollen legs by the evening. Without the calf muscle pump working, fluid pools in the lower legs.
3.3 Hormonal changes & pregnancy
Before menstruation, during pregnancy, or around the menopause, the body retains more water due to hormonal shifts. During pregnancy, mild water retention in the legs and feet is normal and affects up to 80% of pregnant women.
Pregnancy: rule out pre-eclampsia!
Sudden, severe swelling combined with headaches, high blood pressure, and protein in the urine can indicate pre-eclampsia — this is a medical emergency.
3.4 Heart, kidney, or liver disease
In heart failure, blood backs up in the veins and fluid leaks into the tissue. In kidney or liver disease, the body can no longer excrete water adequately. Oedema occurring together with shortness of breath is a warning sign for heart failure.
3.5 Heat and diet
High temperatures dilate blood vessels — which is why swollen legs are particularly common in summer. Too much salt binds water in the body and makes the problem worse.
4. Getting Rid of Water Retention — What Really Works
Immediate measures
Elevate your legs (at least 30 minutes, above heart level), apply cold compresses or run cold water over your calves, circle your feet and wiggle your toes. Wear compression stockings — particularly when standing or sitting for long periods and on long flights.
Long-term measures
Eat a low-salt diet (max. 5–6 g of salt per day), prioritise potassium-rich foods (bananas, potatoes, spinach, avocado), eat sufficient protein, and stay active — particularly exercises that work the calf muscles (climbing stairs, cycling, swimming). Stand up and move briefly every 60 minutes.
Home remedies
Nettle tea and birch leaf tea are traditional home remedies with mild diuretic properties. They do not replace medical treatment, but can provide supportive relief. Asparagus and pineapple also have mildly diuretic properties.
Medical treatment
For medically caused oedema (heart failure, kidney disease), the doctor will prescribe diuretics such as torasemide. For amlodipine-induced oedema, diuretics are ineffective — the doctor may need to switch the active substance.
5. Could Your Medication Be the Cause?
Digital medication plan: Record all your preparations — your doctor can immediately identify oedema-causing active substances.
Interaction check: Find out whether the combination of a blood pressure medication and a painkiller is making the swelling worse.
Dose reminder: For diuretics like torasemide, timing (morning!) is crucial. The reminder ensures you take it at the right time.
FAQ: Frequently Asked Questions About Water Retention
Amlodipine (blood pressure medication) is the most common cause — up to 10% of patients develop ankle oedema. Ibuprofen, diclofenac, and cortisone can also cause oedema.
No. Diuretics like torasemide help with oedema caused by heart or kidney disease, but not with amlodipine-induced oedema or venous insufficiency. The cause determines the treatment.
Nettle tea and birch leaf tea have mild diuretic properties and can provide supportive relief. They do not replace medical treatment — for significant oedema, please see a doctor.
Not automatically. In many cases, drinking enough actually helps because it supports kidney function. Reducing fluid intake is only advisable for heart failure — and only under medical supervision.
Sudden, one-sided swelling of one leg with pain, redness, and warmth. The calf is tender to the touch and feels warm. This is a medical emergency — call 999 or go to A&E immediately!
Sources
ESC Guidelines for Heart Failure (2021) — European Heart Journal
British Society of Phlebology: Chronic venous insufficiency — clinical guidance
NICE guidance: Deep vein thrombosis — diagnosis and management (2023)
brite App: Anonymised user data, as of February 2026
Medical disclaimer: This page is for general informational purposes only and does not replace medical advice. For sudden one-sided swelling, shortness of breath, or rapid weight gain, seek medical help immediately. Last updated: February 2026.
Sudden one-sided leg swelling with pain and redness — seek medical help immediately. Possible DVT!
