What could be the reason for deviation in blood pressure like 140-60 to 140-104?

BecauseYou are Alive: Normal range for Systolic BP is from100 to 140 and and Diastolic ranges from 60 to 80 mm of Hg depending on the age. Women have tendency to run a little lower than the men in general. But at your age 140 is at the upper limit of normal. Anything Above80-85 is also not normal BUT BP fluctuates, Therefore you take BP at various time of the day, Make BP log and bring to your doctor's attention.

Technical inaccuracy: Usually the top number (systolic) and lower number (diastolic) go up and down together within the normal or abnormal range but with some variation. They are both important to control. 140 is borderline high for systolic, while 60 is borderline low and 104 is high for diastolic. Repeat testing and measuring by different means (automated BP machine, manual cuff) can generally sort this out.

Labile BP: Blood pressure is labile and can depend on stress and time of day. Your salt intake that day can also effect your BP readings. If your BP reading is high try relaxing for 5 minutes and retaking your BP. Also try taking your BP several times a day and see when it is running high.

Simple..: Blood pressure is a dynamic number............changes with time,mood, position, food, drink,disease, health, hydration,other medications. Lastly by the instrument,cuff size, ear wax (if stethoscope ) used.

BP always changing: A person's blood pressure is always changing from second to second and moment to moment. The range can be normal most of the time but occasionally higher or lower than normal. A problem occurs when the BP is above normal most of the time and then needs treatment, or if a low or high blood pressure causes symptoms.