The dental pulp in its unique environment has been a tissue of mystery since ages. It behaves strangely and responds unpredictably to various stimuli and treatment. This variability of pulp response has led clinicians to contradictory statements that “the pulp if injured is a dying pulp”, while others with quite an opposite remark that “the pulp cannot be killed with an axe”. Neither the statement is correct and the answer lies somewhere in the midway of the two. When the pulp is injured, it responds with inflam­mation. This in turn increases the vascular permeability and fluid leakage into the surrounding tissue. As the pulp is entirely enclosed within an unyielding chamber of dentin; hence it has no space to swell unlike other soft tissues and this leads to cell death. Moreover, lack of collateral blood supply of the coronal pulp makes it highly compromised in its ability to defend itself from severe irritation. Depending on the severity and duration of the insult and the capacity of the host to respond, the pulpal response ranges from transient inflammation to irreversible pulpitis to total necrosis of the pulp. It is up to the clinician to decide whether the pulp has been reversibly or irreversibly damaged and to manage it accordingly. The dental pulp is a complex and unique tissue. The diagnosis of pulpal disease needs a thorough under­standing of the anatomy, physiology and the pulpal pathogenesis. As the signs and symptoms often tend to overlap, the differential diagnosis is quite an important aid to the operator in successfully treating the patients.