The age of thymus degeneration varies from person to person. Recent studies have shown that thymus development can reach its peak at the age of 1-4 years, followed by a slow degeneration, a significant decrease in thymic tissue and a relative increase in fat after the age of 10 years, and after the age of 60 years, the lymphocyte component of the glandular remnants is very small and becomes mainly fatty tissue. In general, the thymus gland gradually degenerates after puberty and most of the thymus tissue is replaced by adipose tissue, but it still maintains its original shape and still has some endocrine functions and can secrete thymosin.