High pulse rate is where the heart beats faster than usual leaving behind its repercussions. This condition is medically termed as Tachycardia, where the heart beat is abnormally high than the normal rate being 60-100 per every minute. So when a pulse crosses 100 BPM, it is considered to be high due to inability or inefficiency of the heart in pumping the blood.
Tachycardia is of two types. One is ventricular tachycardia, in other words, V-tach, where it is concerned with ventricles; and another being supra-ventricular tachycardia, SVT in which the pumping is in the upper side of the heart. The latter is more common and less harmful than V-tach. Yet, any abnormal condition is better when consulted with a physician.
Causes for these pulse rates to go high are many. But most of them have a short span while there are some factors that keep the pulse rate on high for a comparatively long time. High pulse rate is a factor that is caused by some heart disease in a person. It could be coronary or high BP or pericarditis. The arteries get hardened at times or the valves are damaged that leads to difficult blood pumping. Hyper activity of thyroid leads to high pulse rate. High pulse rate is also caused by other disorders related to metabolism or damage of heart in its upper part thereby straining and weakening the heart.
When the lung tissues get non-elastic, blood pumping is eventually affected. Other factors like fever or vitamin deficiency etc can also be named as temporary causes.