A significant feeling of heaviness in the right leg may be due to the following causes: 1. There may be atrophy of the muscles of the right lower limb. It is often seen when the patient sits or stands for a long time and has a bad posture, such as when the patient has a long period of time with the legs crossed, and this may occur, followed by a feeling of weakness and heaviness. 2. There may be peripheral neuropathy, for example, when a lumbar disc herniation develops, it may cause clinical manifestations such as radioactive pain, numbness and weakness in one lower limb. 3. For example, at the onset of cerebral infarction, there may be an aura of special heaviness and weakness in one lower extremity. 4.It may also be caused by inflammation of the joints of the right lower extremity, for example, when there is osteoarthritis of the knee joint of the right lower extremity, there may be a feeling of weakness and heaviness.