Ageing is structural changes in organs which leads to decreased or loss of functioning. General hypothesis is that old individuals suffer from modifications in immune, metabolic and cognitive systems. At the age of 60 and above male individuals express higher content of creatinine and albumin serum levels compared to females of same age. Older people also contain lesser percentage of differentiated T cells, B cells, reduced antibodies specificity, affinity which leads to impairment in protection against infections. Male individuals are more prone to infections than females at early age of ageing due to decrease in functioning of T-cells. Development of therapies must be differentiated according to gender for old age people due to mark able changes in their in body defence systems.