Our body contains elements like iron and calcium etc. Elements that we see in physical state outside also exist in our body. Either deficiency or excess of those elements in our body is the cause of diseases. We should keep taking a medical test once or twice on a yearly basis at the age of 30-35. At this age our body develops certain changes like the amount of calcium becomes less and the fat called cholesterol starts increasing in our body. Therefore, be aware of your diseases and go get a medical test soon.