Aging and Death
Diseases Associated With Aging
Some consequences of aging are age-related changes in vision, hearing, muscular strength, bone strength, immunity, and nerve function. Glaucoma and cataracts are ocular problems associated with aging that can be treated to restore failing vision in older people. Hearing loss is often noticeable by age 50, and the range of sounds heard decreases. Muscle mass and nervous system efficiency decrease, causing slower reflex times and less physical strength, and the immune system weakens, making older people more susceptible to infections.
More serious diseases of aging include Alzheimer and Huntington diseases. Patients with Alzheimer disease, also called primary dementia, exhibit loss and diminished function of a vast number of brain cells responsible for higher functions; learning, memory, and judgment are all affected. The condition primarily affects individuals over 65 years of age. Some current figures estimate that as many as 10% of people within this age group are affected by Alzheimer disease. A rapidly expanding disease whose numbers increase as the proportion of elderly Americans continues to rise, it is predicted that 14 million people will have Alzheimer disease by the year 2050. Huntington's disease is a severely degenerative malady inherited as a dominant gene. Although
its symptoms do not appear until after age 30, it is fatal, attacking major brain regions. There is no treatment for either of these age-related diseases.