Causes and forms
Edema can have various causes. It is important to see a doctor and check what is causing it to make sure it gets treated correctly.
Edema can be:
- a mild and temporary water retention problem that goes away by itself,
- a symptom of a serious disease that needs treatment,
- a condition that could become chronic and severe (like after cancer treatment or leg edema in one leg following deep vein thrombosis), or
- an adverse effect of medication or an allergic reaction.
General puffiness or swelling caused by water retention
Signs of this kind of edema include puffiness of the hands, feet and / or face. This kind of edema is temporary and goes away without treatment. It can happen because you have been standing or sitting for too long. Edema is common after a long flight, for example, or in people who have to stand for long periods at work. Many women experience edema during their monthly period (menstruation) or during pregnancy. Edema in pregnancy is usually harmless, although it can be a sign of other problems if blood pressure is also high.
Edema related to circulation (vascular), heart or liver problems
A variety of diseases can cause edema. Most of the time, the edema is not a serious illness, but it may be a sign for one. Here are some examples:
Venous insufficiency can cause edema in the feet and ankles, because the veins are having trouble transporting enough blood all the way to the feet and back to the heart. This means that it gathers in the legs, and fluid is forced out of the blood vessels into the surrounding tissue. Edema can also be caused by varicose veins.
Congestive heart failure can cause both peripheral edema and abdominal edema (ascites). This is because the heart is too weak to pump blood around the body properly, so the blood gathers in front of the heart. Because of this, and due to the increased blood pressure in the veins, fluid seeps out into the surrounding tissue. This may cause swelling in the legs or a build-up of fluid in the abdomen. If the person spends a lot of time lying down, the edema might show up on his or her back (called sacral edema). Congestive heart failure can also cause edema in the lungs (pulmonary edema). This is not common, but the condition is life-threatening. It means the lungs are filling with fluid because the left side of the heart is not strong enough to pump the blood returning from the lungs. The blood gathers in the blood vessels of the lung, and fluid seeps out into the lung tissue. The signs are shortness of breath and rapid, shallow breathing or coughing.
Kidney disease could cause edema in the legs and around the eyes, because when the kidneys do not remove enough sodium and water from the body, the pressure in the blood vessels starts building up, which can lead to edema.
Low protein levels in the blood: If there is a lack of the protein albumin in the blood, fluid can leak out of blood vessels more easily. Low protein in the blood can be caused by extreme malnutrition, as well as kidney and liver diseases which mean that the body loses too much or produces too little protein.
Liver diseases: Scarring of liver tissue (liver cirrhosis) due to, for instance, long-term alcohol abuse or a liver , can cause edema in the abdomen (called ascites). This is because cirrhosis causes a lack of proteins and congestion in the liver, which can lead to increased pressure in the blood vessels. As a result, fluid seeps out into the abdomen.
Severe lung conditions like can also cause edema in the legs and feet if the pressure in the lungs and heart gets very high.