It can cause problems in any Organ - like stones in the Gall Bladder or Kidneys. It can appear in and under the skin in the form of lumps. It can be the cause of swelling of the thyroid as well as some fibroids and lipomas. It can block channels, causing numbness. Phlegm can show up about anywhere in the body, but it's especially prone to show up in the Lungs.
Phlegm can the cause of hundred diseases.
Evil Spirit of hundred ailments is the Phlegm. In other words, Phlegm is very versatile in the problems it can cause. Phlegm can figure into some very complex clinical pictures. It can take a long time to resolve Phlegm problems once they get established, and especially after they've been around for a while. The main points to remember is that Qi Stagnation is one of the things which can produce Phlegm, and Phlegm can cause Qi Stagnation.