Hello and welcome to HCM,
Fast
heart rate is caused most commonly due to
anxiety.
The other causes include
hypertension (raised blood pressure) and heart diseases.
Since, your blood pressure is within normal limits, the possibility of hypertension is ruled out.
To rule out heart ailments you need to get examination of your cardiovascular system.
An ECG will determine any problem of the heart.
However, if all the investigations turn out to be normal, anxiety is most common cause.
Pain in the right arm can also be associated with the spells of anxiety.
Management of anxiety is primarily behavioural and social .
You need to find out the cause of anxiety.
Once the cause of anxiety is found out, you need to manage it with support of family and friends.
Thanks and take care
Dr Shailja p Wahal