Final answer:
Tachycardia symptoms of instability typically do not occur when the heart rate is normal, which is between 60-100 bpm for adults. Elevated heart rates can be benign or relate to more serious conditions, and treatment varies accordingly.
Step-by-step explanation:
Tachycardia symptoms of instability are usually not the primary cause when the heart rate is normal. The state of tachycardia occurs when a resting heart rate (HR) exceeds 100 beats per minute (bpm). However, instability symptoms associated with tachycardia, such as dizziness, shortness of breath, palpitations, and fainting, are less typical when the HR is within a normal range of 60-100 bpm for adults. In adults, elevated HR while resting is of concern, but bradycardia, which is a slow HR below 60 bpm, can also be problematic if accompanied by symptoms indicating insufficient oxygenated blood to the tissues. Treatment for tachycardia varies depending on the underlying causes, which can range from benign to life-threatening conditions like cardiomyopathies, valve disorders, or endocrine problems.