What causes aging?
There are several different theories on what causes aging. It is known that free radicals cause damage to many different systems in your body, so this might be one major cause. There is a cellular aging clock, the telomere that seems to shut down some cell types as we age. Your immune system stops functioning correctly, leading to increased chances of external and internal damage. You stop producing some vital hormones as you age, also causing some systems to not function correctly. The good news for biological researchers is that these different causes all overlap in their effects. The bad news is we have yet to sort out which is the root cause.