A harmless faster rhythm, sinus tachycardia is a normal increase in heart rate that happens with fever, excitement, and exercise. There is no need for treatment, except in cases when it is caused by an underlying problem, such as anemia (a low blood count) or hyperthyroidism (overactive thyroid gland), or rarely, happens frequently and without a clear cause (inappropriate sinus tachycardia).
- palpitations, shortness of breath
- dizziness / lightheadedness, chest pain or chest pressure
- heart palpitations (feeling like your heart is racing, pounding, or fluttering)
- pulse that is faster than normal or changing between fast and slow