However, sometimes things do not run smoothly. If the lymphatic system is in any way sluggish (due to being unwell or fatigued), or there is a blockage in any lymph nodes (which can happen without a specific cause), then the amount of fluid the lymphatic system can transport will be less than the load of the swelling. The swelling will persist longer than expected. This can lead to chronic inflammation, and fibrosis of the tissue, which can further impair the lymphatic system. This results in a long term swelling of the body part, which may become painful, heavy and may not function as it used to.