The senescent man had alot of trouble walking up and down the stairs.

voice changes

Senescent psychology is the study of psychology of old age. Senescent issues include forgetfulness, the stress of dealing with illnesses, and possible dementia. As the "Baby Boom" generation ages, there are more and more old people in the population. Senescent psychology will be far more important in the upcoming decades.

Hopefully, you will know that when you are older and more mature.

venerable, doddering, senescent, ancestral