This chapter has proven to be a boon for the medical students as well as practicing clinicians. The efforts given by the author to write this chapter has been appreciated by many students, consultants and practicing doctors. This chapter gives its readers a comprehensive list of clinical illnesses and their etiologies. More so, this chapter has helped the students to score excellent marks in their exams too!! . This chapter, as the name suggests, deals with Symptomatology and its causes. It includes a long list of very frequently encountered clinical problems like Weight gain, Anorexia, Coated tongue, Fever, Bradycardia, Hypothermia, Pyrexia Of Unknown Origin (PUO), Pain, Dyspnoea, Haemoptysis, Palpitations, Hesitancy, Anuria, Constipation, Epistaxis, Hoarsness of voice, Tinnitus, Tingling and numbness; the causes of which are at many a times difficult for both clinicians as well as their patients to interpret. A systematic approach of understanding the etiologies of such commonly presented clinical problems has been clearly explained in this chapter.