Tachycardia is caused by something that disrupts the normal
electrical impulses that control the rate of your heart's pumping
action. Many things can cause or contribute to problems with the
heart's electrical system. These factors include:
Damage to heart tissues from heart disease
Abnormal electrical pathways in the heart present at birth
(congenital)
Disease or congenital abnormality of the heart
Anemia
Exercise
Sudden stress, such as fright
High blood pressure
Smoking
Fever
Drinking too much alcohol
Drinking too many caffeinated beverages
Medication side effects
Abuse of recreational drugs, such as cocaine
Imbalance of
electrolytes, mineral-related substances necessary
for conducting electrical impulses
Overactive
thyroid (hyperthyroidism)...consult physicians they will do the needful