Swollen legs
Swollen legs are a sign, not a diagnosis. The first question is one leg or both. One leg points to a clot, an infection or an injury. Both legs point to the heart, the kidneys, the liver, low protein, a medicine, or pregnancy. A urine dipstick and a look at the neck veins answer much of the rest.
- Setting: Health centre in a small town, 2 hours from a district hospital with a laboratory and visiting physician
- For clinical officers, nurses and doctors at first-level facilities
- Reviewed October 2026
The presentation
Leila, 29, has had swelling of both legs for 3 weeks. Her shoes no longer fit, her eyelids are puffy when she wakes, and her urine has become frothy. She has put on about 5 kg. She is not breathless.
| Vital sign | Value |
|---|---|
| Blood pressure | 134/84 mmHg |
| Pulse | 82 per minute |
| Breathing rate | 16 per minute |
| Temperature | 36.7 °C |
| SpO2 | 98% on air |
| Weight | 68 kg (63 kg 2 months ago) |
Tests at hand: Urine dipstick · Urine pregnancy test · Blood glucose (finger-prick) · Haemoglobin (Hb) · HIV rapid test · Pulse oximetry (SpO2)
- Nephrotic syndromeStill possible
- Heart failure Must not missStill possible
- Pre-eclampsia Must not missStill possible
- Deep vein thrombosis Must not missStill possible
- Acute nephritis or kidney failure Must not missStill possible
- Chronic liver diseaseStill possible
- Low protein from malnutrition or chronic diarrhoeaStill possible
- Medicine side effect (for example amlodipine)Still possible
Work through it
Read each question and decide your own answer first. Then open the model answer and see how the differential changes.
- Step 1 of 7 · Look
Is Leila unwell? What would make leg swelling an emergency?
Model answer
She walked in, is not breathless, and her vital signs are normal. She is not an emergency.
Leg swelling becomes urgent with: breathlessness at rest, crackles or SpO2 below 92% (fluid on the lungs); little or no urine; pregnancy with raised BP; a very high BP; or one leg suddenly swollen and painful, especially with chest pain or breathlessness (a clot).
Pregnancy firstAsk every woman with swelling whether she could be pregnant, and check her BP: pre-eclampsia can present with swelling.Differential now- Nephrotic syndromeStill possible
- Heart failure Must not missStill possible
- Pre-eclampsia Must not missStill possible
- Deep vein thrombosis Must not missStill possible
- Chronic liver diseaseStill possible
- Low protein from malnutrition or chronic diarrhoeaStill possible
- Medicine side effect (for example amlodipine)Still possible
- Acute nephritis or kidney failure Must not missLess likely (moved down)
- Step 2 of 7 · Ask
What do you ask? Organise your questions by cause.
Model answer
- Extent and onset: one leg or both; face or whole body; sudden or over weeks; painful or not.
- Pregnancy: last period, contraception.
- Heart: breathless on exertion or lying flat, waking at night breathless, known heart disease or rheumatic fever.
- Kidney: frothy urine (protein), red or cola-coloured urine, passing less urine, a recent sore throat or skin infection.
- Liver: jaundice, alcohol, hepatitis.
- Low protein: diet, chronic diarrhoea.
- Medicines: amlodipine, painkillers such as ibuprofen, traditional remedies.
- One leg: recent immobility, long travel, surgery, pregnancy, cancer; calf pain; a bite or sore.
- Other: HIV status, diabetes, high BP, sickle cell disease, schistosomiasis.
Both legs, equally, over 3 weeks; puffy eyelids in the mornings. Her period was 10 days ago; she uses an implant. Not breathless, sleeps flat, no heart disease. Frothy urine, normal colour, normal amount; no recent sore throat or skin sores. No jaundice; does not drink alcohol. Eats well, no diarrhoea. No medicines, no remedies. No calf pain, no travel. HIV test 2 years ago negative. No diabetes or high BP known.
Differential now- Nephrotic syndromeLeading (moved up)
- Heart failure Must not missStill possible
- Pre-eclampsia Must not missLess likely (moved down)
- Deep vein thrombosis Must not missLess likely (moved down)
- Acute nephritis or kidney failure Must not missLess likely
- Chronic liver diseaseLess likely (moved down)
- Low protein from malnutrition or chronic diarrhoeaSet aside for now (moved down)
- Medicine side effect (for example amlodipine)Set aside for now (moved down)
- Step 3 of 7 · Look
What do you examine, and what does each sign tell you?
Model answer
- Press firmly over the shin for a few seconds: a dent that stays is pitting oedema (fluid). Non-pitting swelling suggests lymphoedema.
- How far the swelling goes: ankles, shins, thighs, sacrum, face, abdomen (ascites).
- Neck veins and liver: raised neck veins and an enlarged liver suggest heart failure.
- Lungs: crackles or dullness at the bases (fluid).
- Heart: murmurs (valve disease, including RHD).
- Calves: compare both; one swollen, warm and tender suggests a clot.
- Signs of chronic liver disease; pallor; wasting.
Pitting oedema to mid-shin in both legs, equal. Puffy eyelids. No fluid detectable in the abdomen. Neck veins not raised; liver not enlarged. Chest clear; no murmur. Both calves soft and equal, not tender. No jaundice, not pale, not wasted.
Differential now- Nephrotic syndromeLeading
- Heart failure Must not missLess likely (moved down)
- Pre-eclampsia Must not missLess likely
- Acute nephritis or kidney failure Must not missLess likely
- Deep vein thrombosis Must not missSet aside for now (moved down)
- Chronic liver diseaseSet aside for now (moved down)
- Low protein from malnutrition or chronic diarrhoeaSet aside for now
- Medicine side effect (for example amlodipine)Set aside for now
- Step 4 of 7 · Test
Which bedside tests do you do, and what do you expect from each?
Model answer
- Urine dipstick: the key test. Heavy protein (4+ is the nephrotic range) points to the kidneys; blood with protein suggests nephritis.
- Pregnancy test: even with an implant, before deciding the cause and any medicines.
- Glucose: diabetes is a common cause of kidney disease.
- HIV rapid test, with consent: HIV-associated kidney disease often presents with nephrotic syndrome, and the diagnosis is an indication to start ART.
- Haemoglobin: anaemia goes with chronic kidney disease and can worsen heart failure.
- Pulse oximetry: a normal SpO2 makes fluid on the lungs unlikely.
Results: urine protein 4+, no blood, no glucose. Pregnancy test negative. Glucose 5.4 mmol/L. HIV test negative. Hb 12.8 g/dL. SpO2 98%.
Differential now- Nephrotic syndromeLeading
- Heart failure Must not missLess likely
- Acute nephritis or kidney failure Must not missLess likely
- Pre-eclampsia Must not missSet aside for now (moved down)
- Deep vein thrombosis Must not missSet aside for now
- Chronic liver diseaseSet aside for now
- Low protein from malnutrition or chronic diarrhoeaSet aside for now
- Medicine side effect (for example amlodipine)Set aside for now
- Step 5 of 7 · Do
Put it together. What is the most likely diagnosis, and what has been ruled out?
Model answer
Nephrotic syndrome is most likely: generalised pitting oedema with puffy eyelids, frothy urine, heavy proteinuria (4+) without blood, and near-normal BP.
- Heart failure is unlikely: no breathlessness or orthopnoea, neck veins not raised, chest clear, SpO2 normal.
- Pre-eclampsia is excluded: she is not pregnant.
- A clot is unlikely: both legs equally, no calf tenderness, no risk factors.
- Acute nephritis is less likely: no blood in the urine, BP not high, urine output normal, no recent sore throat or skin infection.
- Liver disease and malnutrition are unlikely on history and examination.
She needs blood tests the health centre cannot do (creatinine, albumin, cholesterol), quantification of the protein, tests for causes such as hepatitis B and C, and possibly a kidney biopsy. That is a planned referral within days, not an emergency.
Differential now- Nephrotic syndromeLeading
- Acute nephritis or kidney failure Must not missLess likely
- Heart failure Must not missSet aside for now (moved down)
- Pre-eclampsia Must not missSet aside for now
- Deep vein thrombosis Must not missSet aside for now
- Chronic liver diseaseSet aside for now
- Low protein from malnutrition or chronic diarrhoeaSet aside for now
- Medicine side effect (for example amlodipine)Set aside for now
- Step 6 of 7 · Do
What can you do while she waits for the appointment? What about a diuretic?
Model answer
- Refer within days to the district physician, with a note of the dipstick, BP, weight and tests done.
- Reduce salt: WHO recommends less than 5 g of salt (2 g sodium) a day for adults.
- Raise the legs when sitting, and keep walking.
- Avoid painkillers such as ibuprofen (NSAIDs), which harm the kidneys.
- Weigh her at each visit; a rising weight means more fluid.
- A diuretic such as furosemide is used for bilateral pitting oedema from kidney disease, but it can drop the BP and the potassium. It is best started by the clinician who can check her creatinine and potassium.
- Step 7 of 7 · Ask
What do you tell Leila, and what should bring her back sooner?
Model answer
- Come back the same day if she becomes breathless or cannot lie flat, passes much less urine or red urine, gets a fever or abdominal pain, or if one leg suddenly becomes more swollen and painful.
- Keep the hospital appointment even if the swelling improves.
Your kidneys are letting protein leak into the urine, and that is why your legs and face are swollen. You need blood tests and a kidney check at the hospital this week. Eat less salt, do not take painkillers like ibuprofen, and come back straight away if you get short of breath or pass very little urine.
Must-not-miss conditions
| Condition | Clues | What to do at first-level care |
|---|---|---|
| Heart failure | Breathless on exertion or lying flat, waking breathless, raised neck veins, crackles, enlarged liver, both legs swollen. | Sit up, oxygen if SpO2 low; treat per heart failure protocol; refer the same day if new or now if breathless at rest. |
| Pre-eclampsia | Pregnant beyond 20 weeks, BP 140/90 or more, protein in the urine; headache, visual symptoms, upper abdominal pain. | Per pre-eclampsia protocol: magnesium sulfate and urgent transfer if severe. |
| Deep vein thrombosis | One leg swollen, calf pain and tenderness, warmth; immobility, travel, surgery, pregnancy or cancer. | Refer the same day for assessment; now if chest pain or breathlessness (possible pulmonary embolism). |
| Acute nephritis or kidney failure | High BP, little urine, blood and protein on the dipstick, a recent sore throat or skin infection, swelling of the face. | Refer the same day; now if breathless, confused or no urine. |
| Cellulitis or snakebite | One red, hot, painful leg with fever; a bite with rapidly spreading swelling. | Antibiotics per protocol for cellulitis; snakebite protocol and referral. |
Decision at first-level care
Leila has probable nephrotic syndrome: generalised pitting oedema, puffy eyelids, frothy urine and 4+ protein without blood, with normal neck veins, clear chest and near-normal BP. Heart failure, pre-eclampsia, a clot and nephritis are unlikely. She is referred within days for kidney tests and a cause, with salt reduction, leg elevation, NSAID avoidance and clear return advice meanwhile.
Source: IMAI district clinician manual, volume 2 (2011); WHO Guideline: sodium intake for adults and children (2012).
- Mild ankle swelling on amlodipine with normal urine and no other cause: review the medicine.
- Swelling of both ankles at the end of the day in a healthy person, normal urine, BP and examination: advice and review.
- Mild bilateral swelling with trace protein and normal BP: repeat the dipstick on another day before deciding: proteinuria can be transient.
- Known stable heart failure with small weight gain: adjust treatment per protocol and review in days.
- Breathless at rest, SpO2 below 92%, no urine, or BP 180/110 with symptoms: now.
- One swollen, painful leg (suspected clot): the same day.
- Pregnant beyond 20 weeks with BP 140/90 or more and proteinuria: per pre-eclampsia protocol.
- Heavy proteinuria, blood in the urine, or suspected kidney disease with no clear cause: within days for kidney tests.
- New heart failure: for diagnosis of the cause.
Key learning points
- One leg or both: one points to a clot, infection or injury; both to heart, kidneys, liver, low protein, medicines or pregnancy.
- Ask about pregnancy and check BP in every woman with swelling.
- The urine dipstick is the key bedside test: heavy protein points to the kidneys.
- Neck veins, crackles and SpO2 decide whether this is heart failure.
- Offer an HIV test: HIV-associated kidney disease can present as nephrotic syndrome and is an indication for ART.
Sources
- World Health Organization. IMAI district clinician manual: hospital care for adolescents and adults, volume 2. 2011. Section 10.4, swelling of the limbs: unilateral versus bilateral, history (pregnancy, cardiac, liver, renal, low protein), pitting test, DDx tables (DVT, cellulitis, snakebite; cardiac failure, acute nephritic syndrome, nephrotic syndrome with periorbital oedema and proteinuria, malnutrition, liver disease), investigations, diuretics and symptom management (elevation, walking). Section 11.31: proteinuria 4+ in the nephrotic range; HIV-associated nephropathy presenting as nephrotic syndrome; diagnosis of HIVAN as an indication for ART.
- World Health Organization. Guideline: sodium intake for adults and children. 2012. Less than 2 g sodium (5 g salt) per day for adults.
- World Health Organization. WHO package of essential noncommunicable (PEN) disease interventions for primary health care. 2020 (ISBN 9789240009226). Kidney disease in diabetes and hypertension; urine protein testing (as summarised in the CKD protocol).
- World Health Organization. Managing complications in pregnancy and childbirth: a guide for midwives and doctors, 2nd edition. 2017. Pre-eclampsia after 20 weeks with raised BP and proteinuria.