Sickle cell anemia can cause swollen feet by blocking the flow of oxygen to the extremities, while iron deficiency anemia usually does not. Other potential causes of swollen ankles include medications, certain types of kidney disease and pregnancy.
If you have swollen ankles from anemia, consult your doctor.
Anemia and edema symptoms could be a sign of sickle cell anemia. Or the conditions may be unrelated.
What Causes Swollen Ankles?
According to the Mayo Clinic, swollen ankles may be due to edema — a condition where fluid is trapped in your body's tissues, causing swelling. This swelling can happen anywhere in your body, but is particularly noticeable if it happens in your hands, feet or legs. A number of things can cause edema, including medications, pregnancy, kidney disease, liver disease and congestive heart failure.
Along with swelling, edema may cause stretched or shiny-looking skin, an increased abdominal size and skin that retains a "pit" or dimple after you have pressed down on it for a few seconds. Mild edema can resolve itself in time, but if you have a more serious case of edema, your doctor might recommend taking a diuretic, which can help your body expel excess fluid through your urine.
A swollen ankle can also be caused by a workout injury. If you twist your ankle, drop something on it or land on it with more body weight than you expected, you may see swelling or bruising in the next few days. Try resting your ankle, icing it, keeping it elevated and taking anti-inflammatory painkillers. If you're in serious pain or the swelling doesn't go away within days, you might have a fracture or a more serious injury. See a doctor for a proper diagnosis.
Does Anemia Cause Swollen Feet?
Healthy blood cells are round and flexible and move easily through your blood vessels to deliver oxygen to your organs and tissues. Sickle red blood cells, which are shaped like crescent moons, are rigid and can get stuck in your blood vessels — slowing or even blocking the transport of oxygen. The cells can block blood flow to your hands and feet, causing swelling.
Along with swollen ankles from anemia, other symptoms of sickle cell disease include fatigue and a yellowing of the skin or whites of the eyes. The condition can also cause acute pain episodes when the cells block oxygen flow; these can occur anywhere in the body. The Mayo Clinic says that a bone marrow transplant may cure sickle cell disease, but for the most part, doctors attempt to treat the symptoms. For example, a pain episode can be treated with pain relief medication.
The link between anemia and leg swelling is less clear for other types of anemia. A study published in the Journal of the American Heart Association in January 2015 looked at anemia and chronic kidney disease in 326 patients, using the World Health Organization guideline of hemoglobin concentrations under 13.0 g/dL in men and 12.0 g/dL in women to diagnose anemia.
The ressearchers found that "fluid retention is associated with the severity of anemia," meaning that severely anemic patients with chronic kidney disease also retained a lot of fluid. However, it's not clear whether the fluid retention contributed to the anemia or the anemia led to fluid retention.
Other Types of Anemia
Sickle cell anemia is just one of many forms of anemia. Generally speaking, anemia refers to a condition where the red blood cells are unable to transport enough oxygen around your body — which can be caused by a number of things.
Iron-deficiency anemia, the most common type of anemia worldwide, is caused by insufficient iron levels. Your body requires iron to create hemoglobin, which carries oxygen from the lungs to the rest of the body. Iron-deficiency anemia can be caused by a lack of dietary iron, blood loss through heavy menstruation,
conditions that make it difficult for your body to absorb iron and injury or surgery.
- Vitamin-deficiency anemia is caused by a lack of vitamin B12, folate or vitamin C, either due to a lack of these vitamins in the diet or a condition that makes it difficult to absorb the vitamins. Deficiencies in these vitamins affect your red blood cells, limiting oxygen flow. The Cleveland Clinic says that risk of developing vitamin-deficiency anemia increases with age and during pregnancy.
- Aplastic anemia is a rare blood disorder involving the inability of bone marrow to make enough red blood cells. The condition can be genetic or caused by your immune system attacking cells in your bone marrow. It can also be caused by toxic substances, chemotherapy, radiation, certain medications, infections and pregnancy.
- Anemia of chronic disease occurs when diseases like cancer, HIV/AIDS and Crohn's disease interfere with the production or function of red blood cells. The National Organization for Rare Disorders explains that we don't know exactly what causes anemia of chronic disease. One option is that cancer cells secrete substances that kill red blood cells before they're fully mature. Another possibility is that cancer cells or other diseases get into bone marrow, which is where red blood cells are created in the first place.
Anemia and Edema Symptoms Together
If you have anemia and edema symptoms at the same time, it's possible that the two conditions aren't connected. Swollen ankles from anemia are common with sickle cell anemia, but generally not from other types.
Other common symptoms of anemia include dizziness, feeling weak, pale or "sallow" skin, an increased heartbeat, shortness of breath, a swollen or sore tongue, brittle nails, feeling cold in your hands and feet and craving nonfood items like ice or dirt.
- Mayo Clinic: "Edema"
- Journal of the American Heart Association: "Association of Fluid Retention With Anemia and Clinical Outcomes Among Patients With Chronic Kidney Disease"
- American Society of Hematology: "Anemia"
- Centers for Disease Control and Prevention: "Complications and Treatments of Sickle Cell Disease"
- Mayo Clinic: "Sickle Cell Anemia"
- National Heart, Lung and Blood Institute: "Sickle Cell Disease"
- Mayo Clinic: "Iron-Deficiency Anemia"
- National Heart, Lung and Blood Institute: "Aplastic Anemia"
- Cleveland Clinic: "Vitamin-Deficiency Anemia"
- National Organization for Rare Disorders: "Anemia of Chronic Disease"