You need to visit a cardiologist immediately because increased heart rate can be dangerous. When heart beats more than 100 times in a minute then it contracts before it is completely filled.This causes less blood to pump after each beat leading to less blood flow towards brain. This condition causes dizziness. This increased heart rate can be during exercise which is normal but if it is occurring while resting or with mild exertion then it can be due to
- High blood pressure
- Smoking
- Heart damage due to heart diseases
- Heavy caffeine and alcohol consumption
- Hyperthyroidism
- Electrolyte imbalance
- Drug abuse
- Side effects of medicines
