Chronological age and biological age not the same.  Aging is a physiological process that at times is only remotely connected to how old you are.  How you look is sometimes an indicator of you biological age, but appearances often can be deceptive.Without the diseases of premature aging, normal human life expectancy is estimated to be 120 years.  Most people are capable of living their lives without pain and suffering caused by such chronic degenerative diseases.
Unfortunately, conventional medical care has focused more on symptom relief with pain medications and surgical procedures and less on reversing the accelerated aging process, which is potentially more effective over the long term.  If premature aging can be halted and normal function reestablished, then people not only will live longer but also will have a higher quality of life with the elimination of pain.
Although the disease process and the aging process may run concurrently, they are not the same thing.  You can get sick and even die from many diseases common to old age, but you don't have to get old to have such diseases.  And if you maintain an optimal level of wellness, you should be able to get older without automatically and inescapably being condemned to the pain, discomfort and disabilities associated with many disease states.  Growing old and getting sick simply are not interchangeable or even inextricably linked processes.
Premature aging of the brain, circulation, heart, joints, skin, digestive tract, and immune system can begin at any time of life.  Various factors cause the body to deteriorate, including injuries that do not heal completely, allergies, toxic chemicals, and heavy metals, poor nutrition, excessive radiation sunlight, overwhelming stress, and inactivity.
 Sometimes premature aging occurs without any symptoms until, suddenly, there is a catastrophic event such as a heart attack, cancer, or a stroke.  Other times, atrophy or tissue wasting can occur, as in muscle weakness with lack of exercise, mucous membrane and glandular deterioration with decreased hormone levels and brain atrophy in Alzheimer's disease.
Frequently, however, a body that is aging prematurely sends a message to its owner that it is malfunctioning.  The most common message is pain.  The cause of the pain might include such factors as inflammation, joint instability, insufficient blood supply, or pressure within an organ or on surrounding tissues.The earliest and most obvious signs include men losing their hair and men and women needing reading glasses because of presbyopia (inability to focus on near objects).
A number of characteristic ageing symptoms are experienced by a majority or by a significant proportion of humans during their lifetimes.
Cognitive decline may begin as early as the 20s and 30s.
Wrinkles develop mainly due to photoageing, particularly affecting sun-exposed areas (face)
Around age 35, female fertility declines.
People over 35 years old are at risk for developing presbyopia, and most people benefit from reading glasses by age 45–50. The cause is lens hardening by lifelong depletion of α-crystallin, a process accelerated by elevated ambient temperature.
Hair turns grey with age. Pattern hair loss by the age of 50 affects about half of males and a quarter of females.    Menopause typically occurs between 49 and 52 years of age.
In the 60–64 age cohort, the incidence of osteoarthritis rises to 53%. Only 20% however report disabling osteoarthritis at this age.    Around a third of people between 65 and 74 have hearing loss and almost half of people older than 75.
Frailty, defined as loss of muscle mass and mobility, affects 25% of those over 85.Atherosclerosis is classified as an ageing disease.It leads to cardiovascular disease (for example stroke and heart attack) which globally is the most common cause of death.
Dementia becomes more common with age. About 3% of people between the ages of 65–74 have dementia, 19% between 75 and 84 and nearly half of those over 85 years of age. The spectrum includes mild cognitive impairment and the neurodegenerative diseases of Alzheimer's disease, cerebrovascular disease, Parkinson's disease and Lou Gehrig's disease. Furthermore, many types of memory may decline with ageing, but not semantic memory or general knowledge such as vocabulary definitions, which typically increases or remains steady until late adulthood. Intelligence may decline with age, though the rate may vary depending on the type and may in fact remain steady throughout most of the lifespan, dropping suddenly only as people near the end of their lives. Individual variations in rate of cognitive decline may therefore be explained in terms of people having different lengths of life. There might be changes to the brain: after 20 years of age there may be a 10% reduction each decade in the total length of the brain's myelinated axons.
 Age can result in visual impairment, whereby non-verbal communication is reduced,which can lead to isolation and possible depression. Macular degeneration causes vision loss and increases with age, affecting nearly 12% of those above the age of 80. This degeneration is caused by systemic changes in the circulation of waste products and by growth of abnormal vessels around the retina.A distinction can be made between "proximal ageing" (age-based effects that come about because of factors in the recent past) and "distal ageing" (age-based differences that can be traced back to a cause early in person's life, such as childhood poliomyelitis).Ageing is among the greatest known risk factors for most human diseases. Of the roughly 150,000 people who die each day across the globe, about two thirds—100,000 per day—die from age-related causes. In industrialised nations, the proportion is higher, reaching 90%