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Since your age is 48yrs and you got chest pain
while walking it can be due to Angina (less blood supply & oxygen
supply to heart.This is a unstable angina
coming on exertion.Please visit a Cardiologist /hospital & get a ECG done.You will require a thorough investigation of cholesterol/triglycerides/and cardiac profile.The Cardiologist may also advise you STRESS test
(continuous ECG is taken while walking on a treadmill) to confirm that the pain is of heart & then prescribe treatment for that.
Please visit a Cardio ASAP.