Differential Diagnosis for Ankle Swelling without Injury

Single Most Likely Diagnosis

• Dependent Edema: This is a common condition where fluid accumulates in the ankles and feet due to gravity, especially in individuals who stand for long periods or have poor circulation. It's often seen in people with sedentary lifestyles or those who have been on long flights.

Other Likely Diagnoses

• Chronic Venous Insufficiency: A condition where the veins have problems returning blood from the legs back to the heart due to issues like valve problems. This leads to blood pooling in the legs, causing swelling.
• Lymphedema: Swelling caused by impaired lymph drainage, which can be primary (inherited) or secondary (due to surgery, infection, or trauma).
• Hypothyroidism: An underactive thyroid gland can cause swelling in the legs, among other symptoms like fatigue and weight gain.
• Medication Side Effects: Certain medications, such as calcium channel blockers, steroids, and certain antidepressants, can cause ankle swelling as a side effect.

Do Not Miss Diagnoses

• Deep Vein Thrombosis (DVT): A blood clot in the deep veins of the legs. Although it often presents with pain, it can sometimes be painless, making it crucial not to miss.
• Cellulitis: A bacterial skin infection that can cause swelling, redness, and warmth. It requires prompt antibiotic treatment.
• Heart Failure: Swelling in the ankles can be a sign of right-sided heart failure, where the heart is not pumping efficiently, leading to fluid buildup.
• Nephrotic Syndrome: A kidney disorder that causes the body to excrete too much protein in the urine, leading to low albumin levels, which in turn causes fluid to leak out of blood vessels and into tissues, resulting in swelling.

Rare Diagnoses

• Sarcoidosis: A disease characterized by the growth of granulomas (inflammatory cells) in various parts of the body, which can cause swelling in the ankles among other symptoms.
• Amyloidosis: A condition where abnormal proteins (amyloid) accumulate in organs and tissues, potentially causing swelling.
• Fabry Disease: A rare genetic disorder that can cause swelling in the feet and hands due to the buildup of a particular type of fat in the body's cells.
• Lipedema: A chronic condition characterized by the abnormal growth of fat cells in the legs, leading to swelling and pain.