There are several reasons why fluid retention (edema) occurs in the legs, ranging from standing for long periods and certain medications to underlying medical conditions that require attention.

While many causes of fluid retention are not concerning, it should not be ignored. It is essential to consult a doctor, especially if the swelling is accompanied by other symptoms, to rule out serious health conditions.

What Causes Fluid Retention in the Legs?

The causes of fluid retention are classified into non-medical and medical causes as follows:

Non-Medical Causes

These are the most common causes and include: (1)(2)

  • Prolonged standing or staying in the same position for extended periods, such as during long-distance travel.
  • Excessive salt intake, such as eating pickles and salty foods, which promote fluid retention in the body.
  • Excess body weight (obesity).
  • Pregnancy.
  • Premenstrual symptoms, occurring about two weeks before menstruation.
  • Hot weather in the summer.
  • Vitamin B1 deficiency.
  • Certain medications, including: 
  • Blood pressure medications.
  • Oral contraceptives (birth control pills).
  • Corticosteroids.
  • Some anti-inflammatory drugs, such as ibuprofen.
  • Certain antidepressants.
  • Some oral diabetes medications. (3)

Medical Causes

In some cases, fluid retention may be a sign of a more serious health condition, including: (3)(4)

  • Chronic venous insufficiency (CVI): A common condition where the valves in the leg veins weaken, making it difficult for blood to flow back to the heart, leading to fluid buildup in the lower legs.
  • Heart failure: A condition where the heart’s pumping ability weakens, causing blood to back up into the legs and ankles, resulting in swelling.
  • Kidney disease: When the kidneys fail to eliminate excess fluids and salts, they accumulate in the legs and around the eyes. Nephrotic syndrome is another kidney condition that affects the filtration system, leading to protein loss in the blood and fluid retention.
  • Liver cirrhosis: Patients with cirrhosis often experience fluid buildup in the abdomen and, in some cases, swelling in the legs.
  • Deep vein thrombosis (DVT): If swelling occurs in only one leg, along with redness and pain, it may indicate a blood clot, which is a medical emergency.
  • Angioedema: A sudden swelling that can affect the face, lips, tongue, throat, or limbs, sometimes accompanied by breathing difficulties and difficulty swallowing. It can be caused by certain medications (such as blood pressure drugs) or genetic conditions.
  • Lymphatic system disorders: These may occur after cancer surgery, impairing the body’s ability to drain fluids properly.
  • Malnutrition: Severe protein deficiency in the diet can lead to fluid retention.


When Should You See a Doctor?

Although many cases of fluid retention are not serious, medical attention is required if you experience any of the following: (5)

✔ Persistent swelling that does not subside after some time.

✔ Swelling observed first thing in the morning.

✔ Pain, redness, or warmth in one leg but not the other.

✔ Accompanying symptoms, such as:

  • Shortness of breath.
  • Decreased urine output.
  • Swelling around the eyes.
  • Noticeable abdominal swelling.
  • Other concerning symptoms.

📅 Book an appointment at Al-Ahli Hospital to receive an accurate diagnosis and effective treatment for fluid retention.

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