by mueni
(nairobi)
Question from Mueni: My mother has diabetes. Her foot becomes swollen and hard in the afternoon but looks normal again in the morning. She has not attended the clinic for a long time. What could be causing this?
A new swollen foot in a person with diabetes needs prompt medical assessment, especially when it is hard, warm, red, painful, numb, or affects only one side. Afternoon swelling that improves overnight can occur with dependent edema or venous insufficiency, but it does not by itself diagnose heart failure.
Your mother should arrange a clinic visit as soon as possible for a foot, circulation, heart, kidney, medication, and glucose review. Seek same-day urgent care if one foot is hot, red, markedly swollen, newly deformed, or has a wound. Call emergency services for sudden breathlessness, chest pain, coughing blood, fainting, or severe weakness.
Answer by Dr. Albana Greca, MD, MMedSc
Dear Mueni,
Please do not wait for the swelling to become permanent. Diabetes can reduce sensation, circulation, and healing, so a foot problem may become serious even when pain is mild. Our guide to daily diabetic foot care explains the warning signs that should be checked every day.
Swelling that becomes worse after standing or sitting and improves after lying down often occurs when fluid collects in the lower legs. Varicose veins, reduced calf-muscle movement, excess weight, or damaged vein valves may contribute. This pattern is common, but a clinician must still exclude more urgent causes.
A deep-vein thrombosis usually causes swelling in one leg or foot and may also cause calf pain, tenderness, warmth, or redness. Visible blue veins do not confirm or exclude a clot. Do not massage the swollen leg. Sudden breathlessness or chest pain may indicate a pulmonary embolism and is an emergency.
Cellulitis, an infected blister, ulcer, nail problem, or small unnoticed injury can cause swelling, warmth, redness, tenderness, drainage, or fever. Neuropathy may reduce pain, so inspect between the toes and under the foot. Our diabetic foot-ulcer guide explains when wounds require urgent treatment.
The old term “Charcot’s atrophy” is incorrect. Active Charcot foot is a serious diabetes-related bone and joint disorder, usually occurring with neuropathy. The foot may become hot, red, and swollen, sometimes with little pain and no obvious injury. Walking on it can cause fractures and permanent deformity.
If Charcot foot is possible, she should avoid weight-bearing and receive same-day specialist assessment. Early immobilization and offloading are essential.
Heart failure can cause swelling of both feet and ankles, often with breathlessness, difficulty lying flat, fatigue, rapid weight gain, or abdominal swelling. Afternoon swelling alone does not prove heart failure.
Diabetic kidney disease may cause fluid retention, often in both legs, and may be associated with protein in the urine, reduced kidney function, high blood pressure, or swelling around the eyes. Learn more in our guide to diabetes and kidney disease. Advanced liver disease can also cause generalized fluid retention, but it cannot be diagnosed from the texture of the swelling.
Some medicines can cause edema, including amlodipine and other calcium-channel blockers, anti-inflammatory pain medicines, steroids, hormone treatments, and thiazolidinediones such as pioglitazone. Injury, gout, arthritis, lymphedema, thyroid disease, and prolonged immobility are other possibilities.
The clinician should determine whether one or both feet are affected and examine the skin, temperature, wounds, pulses, sensation, capillary refill, veins, joints, and footwear. Useful checks may include blood pressure, weight, glucose or HbA1c, kidney function, urine albumin, liver tests, and a medication review.
Depending on the findings, Doppler ultrasound may be needed for a suspected blood clot or venous disease. A hot swollen neuropathic foot may need an X-ray and sometimes MRI, but treatment should not be delayed when active Charcot is strongly suspected.
If swelling is mild, affects both ankles, and there are no urgent warning signs, resting with the legs elevated may reduce dependent edema temporarily. It should not replace an examination.
Get same-day care for a hot, red, rapidly enlarging, very painful, numb, or newly deformed foot; a wound, pus, fever, black skin, or swelling mainly on one side. Call emergency services for chest pain, sudden breathing difficulty, coughing blood, collapse, confusion, or severe weakness.
Swelling that worsens during the day often reflects gravity and venous pressure, but the pattern is not specific enough to diagnose the cause. In a person with diabetes, I would first exclude infection, a blood clot, active Charcot foot, and impaired circulation before treating it as simple fluid retention.
Educational only: This answer does not replace an urgent foot examination or an individualized medical assessment.
Last reviewed: July 2026.
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