It is very important to see a doctor right away to find out why you have swelling. You should make sure there is no other cause of the swelling that needs immediate treatment, like a blood clot.

First, your doctor will examine you and ask you when you first noticed the problem. If your arm or leg is swollen, your doctor may measure it to compare it with your other arm or leg. Usually, if your swollen arm or leg is 2cm (about 4/5 of an inch) bigger than your other arm or leg, you have lymphedema.

Your doctor may also suggest other tests to find out if you have lymphedema and if so, what is causing it. Lymphoscintigraphy is a test that uses radioactive material to see if the lymph vessels are blocked. Other X-ray tests may be done to see what is causing the swelling. Computed tomography (CT) scans can take pictures of the swollen area to find out why the lymph vessels are blocked.