A sensor guide wire for an intravascular measurement of at least one variable in a living body, wherein the sensor guide wire has a proximal region , a distal sensor region and a tip region , the sensor guide wire comprising: a sensor element arranged in the sensor region , the sensor element comprising a sensor portion configured to measure the variable and to generate a sensor signal in response to the variable; a jacket enclosing at least part of the sensor element , wherein the jacket includes at least a sensor opening , and wherein a distal end of the jacket is located distal of the sensor element ; and a core wire , having a longitudinal axis (A) and comprising at least a tip core wire portion extending along said tip region of the sensor guide wire ; wherein the tip core wire portion comprises: a proximal portion, an intermediate portion located distal of the proximal portion, a diameter (D 2 ) of the intermediate portion being less than a diameter of the proximal portion, and a distal tip including an enlargement , a diameter (D 1 ) of the enlargement being greater than the diameter (D 2 ) of the intermediate portion ; a polymer layer is disposed directly on the intermediate portion of the tip core wire portion ; the proximal portion of the tip core wire portion , the intermediate portion of the tip core wire portion , and the distal tip of the tip core wire portion are formed integrally as a single piece; a proximal end of the polymer layer extends distally from the distal end of the jacket ; and a distal end of the polymer layer extends proximally from a proximal end of the enlargement of the distal tip . a sensor element arranged in the sensor region , the sensor element comprising a sensor portion configured to measure the variable and to generate a sensor signal in response to the variable; a jacket enclosing at least part of the sensor element , wherein the jacket includes at least a sensor opening , and wherein a distal end of the jacket is located distal of the sensor element ; and a core wire , having a longitudinal axis (A) and comprising at least a tip core wire portion extending along said tip region of the sensor guide wire ; wherein the tip core wire portion comprises: a proximal portion, an intermediate portion located distal of the proximal portion, a diameter (D 2 ) of the intermediate portion being less than a diameter of the proximal portion, and a distal tip including an enlargement , a diameter (D 1 ) of the enlargement being greater than the diameter (D 2 ) of the intermediate portion ; a proximal portion, an intermediate portion located distal of the proximal portion, a diameter (D 2 ) of the intermediate portion being less than a diameter of the proximal portion, and a distal tip including an enlargement , a diameter (D 1 ) of the enlargement being greater than the diameter (D 2 ) of the intermediate portion ; a polymer layer is disposed directly on the intermediate portion of the tip core wire portion ; the proximal portion of the tip core wire portion , the intermediate portion of the tip core wire portion , and the distal tip of the tip core wire portion are formed integrally as a single piece; a proximal end of the polymer layer extends distally from the distal end of the jacket ; and a distal end of the polymer layer extends proximally from a proximal end of the enlargement of the distal tip . <EOS>