Swollen Ankles and Feet: Causes, Warning Signs and Which Tests Help
The essentials
Swollen ankles are usually fluid pulled down by gravity: long sitting or standing, weak leg veins or a blood pressure pill. One painful swollen leg, or swelling with shortness of breath, is urgent. Lasting swelling in both legs calls for blood and urine tests of the heart, kidneys, liver and thyroid.
About 1 in 5 adults over 50 has some leg swelling[1]. Doctors ask: one leg or both, sudden or slow, and what else you feel[2]. A thumb pressed on the skin that leaves a dent means "pitting" edema, the common kind[2].
When are swollen ankles an emergency?
When to see a doctor
- Emergency: call 911 for swelling with shortness of breath, chest pain, coughing up blood or fainting: a clot may have reached the lungs (pulmonary embolism)[3][4]. In pregnancy, get help at once for a swollen face or hands with a severe headache, vision changes or upper belly pain (possible preeclampsia)[6].
- Today for one swollen, painful or warm leg, especially after a flight, surgery or bed rest (possible clot)[1][4]; a red, hot leg with fever; a sudden rise in swelling in pregnancy; or worse swelling with known heart, kidney or liver disease[3].
- At your next appointment for swelling in both ankles that lasts despite raising your legs and walking, started with a new medicine, or comes with puffy eyes or foamy urine[4][10].
Why are my ankles and feet swollen? Everyday causes first
- Common Gravity. Standing or sitting for hours, long trips, extra weight and salty meals let fluid pool. It improves when you raise your legs or lie down[2][4].
- Common Weak leg veins (chronic venous insufficiency). Vein valves no longer push blood back up well, often with varicose veins; over years the skin near the inner ankle may turn brownish[2][3].
- Common Medicines. Calcium channel blockers such as amlodipine are the classic culprit: in 106 trials, swelling affected 10.7% of people taking them versus 3.2% on placebo[12]. NSAID painkillers, steroids, hormones and some antidepressants can also do it[2][3]. Never stop a medicine without asking the prescriber.
- Common Pregnancy. Mild ankle swelling is normal[5].
Which medical conditions cause swollen ankles?
- Possible A blood clot in a leg vein. One leg, swollen within hours or days, often painful[2]. See deep vein thrombosis and blood clot warning signs.
- Possible Heart failure. Both legs, with breathlessness on exertion or lying flat, or quick weight gain[1]. The tests that confirm it are in heart failure diagnosis.
- Possible Kidney disease. Legs, and puffy eyelids in the morning, sometimes with foamy urine; heavy protein loss is called nephrotic syndrome[10]. See chronic kidney disease.
- Possible Liver disease. In cirrhosis, the belly often swells too[1].
- Possible Thyroid problems and sleep apnea. Thyroid disease can swell the legs, sometimes as firm swelling that does not dent[1][4]; so can sleep apnea[2].
- Possible Skin infection. Cellulitis makes one leg red, hot and tender[4].
- Rare Lymphedema, preeclampsia. Lymphedema comes from damaged lymph vessels[2]. Preeclampsia starts after 20 weeks of pregnancy, with high blood pressure[5].
What tests will the doctor do for swollen ankles?
For lasting swelling in both legs, a common first round is NT-proBNP (or BNP), a metabolic panel, liver tests, TSH and urine protein. For one leg, the question is a clot: D-dimer or ultrasound[1].
| Test | What it answers | Usually when |
|---|---|---|
| NT-proBNP or BNP | Is the heart under strain? | Both legs, breathlessness |
| Creatinine and eGFR | Do the kidneys filter well? | Both legs, diabetes |
| Albumin | Is blood protein low? | Puffy eyes, liver disease |
| Urine protein (urinalysis, albumin-to-creatinine ratio) | Do the kidneys leak protein? | Foamy urine, puffy eyes |
| Liver tests (ALT, AST, bilirubin) | Is the liver involved? | Alcohol, swollen belly |
| TSH | Is the thyroid involved? | Fatigue, weight change |
| D-dimer | Can a clot be ruled out? | One leg, low clot probability |
| Doppler (duplex) ultrasound | Clot or leaking vein valves? | One leg; chronic swelling |
Creatinine, albumin and liver tests come together in a comprehensive metabolic panel. A high NT-proBNP leads to a heart ultrasound[1].
BloodSense explains your whole report line by line, in plain words, so you know what to ask your doctor.
Explain my resultsHow do I read my results?
| Test | Result | Reference range | Flag |
|---|---|---|---|
| NT-proBNP | 610 pg/mL | 0-125 pg/mL | H |
| Creatinine | 1.0 mg/dL | 0.6-1.1 mg/dL | |
| eGFR | 58 mL/min/1.73 m² | ≥60 | L |
| Albumin | 4.0 g/dL | 3.4-5.4 g/dL | |
| TSH | 2.3 mIU/L | 0.4-4.5 mIU/L |
- H means above this lab's range. At 610, guidelines advise a heart ultrasound and a specialist review within 6 weeks[7].
- Creatinine is normal, but the eGFR (calculated from it, age and sex) is just under 60: possible kidney disease, to recheck[9].
- Albumin is normal: low blood protein is not the cause[8].
NT-proBNP and BNP: does the heart explain the swelling?
A stretched heart releases these peptides; a normal level usually makes heart failure unlikely[11]. UK guidelines read NT-proBNP below 400 pg/mL in an untreated person as "heart failure less likely", 400 to 2,000 as heart ultrasound within 6 weeks, above 2,000 within 2 weeks. Kidney and lung disease raise the level; obesity, diuretics and other heart medicines lower it[7].
Kidneys, albumin and urine protein
An eGFR of 60 to 90 may mean early kidney disease, 15 to 60 kidney disease[9]. Albumin is normally 3.4 to 5.4 g/dL[8]. Low albumin with much urine protein is the nephrotic pattern[10]; low albumin with clean urine points to the liver or poor nutrition[2]. Foamy urine has other causes too: cloudy or foamy urine.
D-dimer and ultrasound for one swollen leg
When a clot is unlikely, a negative D-dimer rules it out. It catches 96% of clots but is often positive without one (specificity 35%), so a high result leads to ultrasound; when a clot is likely, ultrasound comes first[1]. Pregnancy, surgery, older age and immobility raise D-dimer[11].
What should I note before the appointment?
- One leg or both; sudden or gradual
- Better after a night or with legs raised? Does a thumb press leave a dent?
- Breathlessness, extra pillows at night, weight gain; puffy eyes, foamy urine, swollen belly
- All medicines, with start dates (blood pressure pills, painkillers, hormones)
- Recent flight, surgery or bed rest; pregnancy
Frequently asked questions
How do I know if my swollen ankles are heart related?
Heart swelling affects both legs and usually comes with breathlessness, especially lying flat[1]. A normal NT-proBNP makes a heart cause unlikely[11].
Should I take a water pill for swollen ankles?
Not on your own. For vein swelling, diuretics are avoided unless another condition needs them; raising the legs, walking and compression stockings come first[2][3].
Can amlodipine cause swollen ankles?
Yes, more often at higher doses and with longer use[12]. Your prescriber can change the dose or the medicine.
Related tests and guides
- Heart failure diagnosisBNP, NT-proBNP and the echocardiogram explained.
- NT-proBNP testWhat your level means for the heart.
- eGFR blood testHow to read your kidney filtration number.
- Blood clotsWarning signs and the tests that find them.
References
- Patel H, Skok CJ, DeMarco A. Peripheral edema: evaluation and management in primary care. Am Fam Physician. 2022;106(5):557-564. aafp.org (accessed November 9, 2026)
- Trayes KP, Studdiford JS, Pickle S, Tully AS. Edema: diagnosis and management. Am Fam Physician. 2013;88(2):102-110. aafp.org (accessed November 9, 2026)
- MedlinePlus Medical Encyclopedia. Foot, leg, and ankle swelling. medlineplus.gov (accessed November 9, 2026)
- NHS. Swollen ankles, feet and legs (oedema). nhs.uk (accessed November 9, 2026)
- MedlinePlus Medical Encyclopedia. Preeclampsia. medlineplus.gov (accessed November 9, 2026)
- American College of Obstetricians and Gynecologists. Preeclampsia and high blood pressure during pregnancy (FAQ). acog.org (accessed November 9, 2026)
- National Institute for Health and Care Excellence. Chronic heart failure in adults: diagnosis and management (NG106). nice.org.uk (accessed November 9, 2026)
- MedlinePlus Medical Encyclopedia. Albumin blood test. medlineplus.gov (accessed November 9, 2026)
- MedlinePlus Lab Tests. Glomerular filtration rate (GFR) test. medlineplus.gov (accessed November 9, 2026)
- MedlinePlus Medical Encyclopedia. Nephrotic syndrome. medlineplus.gov (accessed November 9, 2026)
- MedlinePlus Lab Tests. Natriuretic peptide tests (BNP, NT-proBNP); D-dimer test. medlineplus.gov, medlineplus.gov (accessed November 9, 2026)
- Makani H, et al. Peripheral edema associated with calcium channel blockers: incidence and withdrawal rate.. J Hypertens. 2011;29(7):1270-1280. doi:10.1097/HJH.0b013e3283472643 (accessed November 9, 2026)
This article is general health information. It does not replace a medical examination, diagnosis or treatment. Do not stop a medicine or start a diuretic without talking to your doctor.
