The present disclosure concerns methods of detecting levels of one or more molecules(s), longevity predicting marker(s), in a sample, and using these levels of the marker(s) to predict a condition. In a particular embodiment, the present invention concerns methods of detecting longevity predicting marker(s), in a sample, preferably to assess the overall health status in a subject predisposed to a condition. In certain embodiments, the methods may comprise obtaining a sample from a subject such as a blood, saliva or buccal swab sample and analyzing the sample for the presence or level of a longevity predicting marker(s) to predict a condition. In another embodiment, the methods may comprise analyzing a sample from a subject for the presence of longevity predicting marker(s) and applying information obtained from analyzing the presence of longevity predicting marker(s) to determine a treatment for a medical condition of the subject.