compensatory hypertrophy

Compensatory growth is a biological process where an organ or body part increases in size to compensate for the loss or reduced function of a paired organ or part. This can occur through an increase in cell size (hypertrophy), an increase in cell number (hyperplasia), or both.

A common example is the kidney: if one kidney is removed, the remaining kidney will enlarge to take over the function of both. This compensatory reaction helps the organism adapt and maintain normal bodily functions. While cell division increases the size of functional units like glomeruli in the kidney, it doesn't necessarily increase their total number. This phenomenon is also observed in endocrine organs, where stimulation can lead to significant increases in cell size. In contrast, secondary hyperparathyroidism is a compensatory response to low calcium levels, where the parathyroid glands become overactive.12