Visualisation is the use of the imagination to create pictures of desired situations or conditions. With any visualisation technique, the more powerful and complete the picture, the greater the response. Consciously using visualisations allows participants to use the imagination in a structured way, providing clear links with dreams and desires and thus allowing relaxation and the control of the physical symptoms of disease. Put simply, by thinking about feeling good, you will feel good. In addition, by trying to visualise how our bodies appear internally, we may attempt to overcome some common physical illnesses such as hypertension (high blood pressure). Some people also believe that effective visualisation focused on improving the efficacy of the immune system can slow down the rate of progression of cancer and AIDS, although this remains a topic of considerable debate. Visualisations allow exponents to reinforce feelings and thus combat stress and some of the physical manifestations of disease.