Common Causes of Swelling oedema
1. Heart Failure
Heart failure causes fluid retention through reduced cardiac output, leading to leg and ankle oedema (pitting), breathlessness on exertion or lying flat, fatigue and reduced exercise tolerance. NT-proBNP is an important biomarker.
2. Kidney Disease (Nephrotic Syndrome, CKD)
Kidney disease causes oedema through multiple mechanisms: low albumin in nephrotic syndrome leads to generalised oedema (legs, face, abdomen); chronic kidney disease causes fluid retention through impaired excretion. Urine protein and kidney function tests are key.
3. Liver Disease
Advanced liver disease leads to low albumin production, portal hypertension and ascites (abdominal fluid). Leg oedema, abdominal swelling, jaundice and altered consciousness may occur.
4. Hypothyroidism
Severe hypothyroidism causes a non-pitting swelling (myxoedema) affecting the face, legs and skin. Associated with fatigue, cold intolerance, weight gain, constipation and dry skin. TSH is the key test.
5. Deep Vein Thrombosis (DVT)
Blood clot in a leg vein causes unilateral (one-sided) leg swelling, warmth, redness and tenderness. DVT is a serious condition as the clot can travel to the lung (pulmonary embolism). Requires urgent evaluation.
6. Venous Insufficiency
Chronic poor venous drainage in the legs causes dependent oedema worsening through the day, varicose veins, skin changes and ulcers. Common with prolonged standing, obesity and previous DVT.
7. Malnutrition & Hypoalbuminaemia
Very low protein intake or protein loss causes low serum albumin, resulting in oedema. Seen with severe malnutrition, chronic illness, malabsorption and nephrotic syndrome.
8. Medications
Many medications cause fluid retention: amlodipine and other calcium-channel blockers (very common), some NSAIDs, hormones (oestrogen, testosterone), corticosteroids, some diabetes drugs (glitazones) and others.
9. Pregnancy
Mild ankle and feet swelling is common in pregnancy due to increased blood volume and uterine pressure on pelvic veins. Sudden or severe swelling with headache or high blood pressure may indicate pre-eclampsia — a medical emergency.
10. Lymphoedema
Impaired lymphatic drainage causes chronic non-pitting swelling. May follow cancer treatment, infection, surgery or be congenital.
⚠️ When Should You Seek Medical Care?
Seek urgent medical attention if you experience any of the following:
- 🚨 Sudden severe swelling of a single leg with pain and redness — possible DVT/clot
- 🚨 Swelling with sudden severe breathlessness — possible pulmonary embolism
- 🚨 Facial swelling with difficulty breathing — allergic emergency (anaphylaxis)
- 🚨 Severe swelling in pregnancy with headache or high blood pressure — possible pre-eclampsia
- Rapidly increasing abdominal swelling (ascites)
- Swelling with jaundice (yellow eyes/skin)
- Swelling with significantly reduced urine output
- Swelling with sudden confusion or altered consciousness
- Generalised swelling involving face, abdomen and legs together
Which Laboratory Tests May Be Considered?
Clinical note: Laboratory tests should be selected by a doctor based on your symptoms, history and clinical examination. Not every person requires all of the tests listed below.
| Test | Why a Doctor May Consider It |
|---|---|
| Kidney Function Tests (Urea, Creatinine, eGFR) | To assess renal cause of oedema |
| Urine Routine & Protein:Creatinine Ratio | Proteinuria is a key feature of nephrotic syndrome |
| Serum Albumin | Low albumin causes oedema from reduced oncotic pressure |
| Liver Function Tests | For suspected liver disease contributing to oedema |
| NT-proBNP | Key biomarker for heart failure — elevated when cardiac cause is suspected |
| CBC | For anaemia, infection, blood disorders |
| TSH | Hypothyroidism causes non-pitting oedema (myxoedema) |
| Electrolytes | Low sodium and other electrolyte abnormalities with oedematous states |
| D-Dimer | For suspected DVT — high sensitivity, low specificity; useful to exclude in low-risk patients |
Frequently Asked Questions
Is leg swelling always a sign of heart failure?
No. Leg swelling has many causes including kidney disease, liver disease, venous insufficiency, medications and hypoalbuminaemia. However, bilateral ankle and leg oedema with breathlessness warrants investigation for heart failure.
What is the difference between pitting and non-pitting oedema?
Pitting oedema leaves a temporary pit when pressed — common with heart failure, kidney disease, venous insufficiency and hypoalbuminaemia. Non-pitting oedema does not pit — seen with hypothyroidism (myxoedema) and lymphoedema.
Can my blood pressure medication cause swelling?
Yes. Amlodipine and other dihydropyridine calcium-channel blockers commonly cause ankle and leg swelling as a side effect. Discuss with your doctor before stopping the medication.
QXL Diagnostic Support
QXL Diagnostics provides kidney function, urine protein, serum albumin, liver function, NT-proBNP, TSH and electrolyte testing with home collection across Bengaluru.
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Medical Review
Medically reviewed by: Dr. Shantakumar Muruda, MD - Medical Biochemistry; Founder & CEO, QXL Diagnostics Super Speciality Lab, Bengaluru
Last medically reviewed: 2026-09-11
Clinical reference framework:Harrison's Principles of Internal Medicine; Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics; and relevant specialty guidance as clinically appropriate.
Medical Disclaimer: This information is intended for general health education and does not diagnose an individual medical condition. It does not replace consultation, diagnosis or treatment by a qualified healthcare professional. Seek urgent medical attention for severe, sudden or rapidly worsening symptoms or any emergency warning signs described above.