People perceive pain differently and the degree of degeneration varies among individual. In general, when degeneration becomes severe, pain will increase and even affect daily life. For example, those who suffered from chronic pain may not be able to walk for a long distance or long time and may have trouble lifting their arms. These difficulties may affect their self-care and mobility, which in the long run, could impose negative impact on their mood and social life, and eventually lead to depression.