What is hypertrophy defined as?

Hypertrophy is specifically defined as an increase in cell size. This process occurs when individual cells enlarge, often in response to increased workload or stress. When we refer to hypertrophy in the context of organs or tissues, it is important to note that this enlargement is due to the increased size of existing cells, rather than an increase in the number of cells, which would be classified as hyperplasia.

In essence, hypertrophy leads to a larger organ size due to the growth of its constituent cells, but it does not involve an increase in cell numbers. This distinction is crucial in understanding how tissues adapt to various stimuli, such as exercise or hormonal signals. When tissues like muscle undergo hypertrophy, such as in resistance training, the strength and size of the muscle fibers increase, resulting in a stronger and larger muscle without an increase in the number of muscle cells. Therefore, the correct definition aligns with the growth of cell size rather than cell number or overall tissue volume without changes at the cellular level.