More than 70,000 live organ donations have been performed in the U.S. Of these, kidney and lung donations constitute 90% and 0.8%, respectively. Although, the rates of postoperative donor complications are known to be 8-10% for donor nephrectomy and 20-60% for donor lung lobectomy, the donor long-term medical and quality of life outcomes following live kidney or lung donation have not been well studied. Observational studies in kidney donors have found prevalent disease rates similar to the overall U.S. population for hypertension (30-35%), chronic kidney disease [CKD] (1%) and type 2 diabetes mellitus (5%). A six-fold increased risk of postdonation psychological impairment has been reported in small, poorly controlled series. In the aggregate, existing studies are limited by 1) incomplete donor follow-up rates of 30- 60% and 2) absent or methodologically deficient comparator groups. A consortium of 10 clinical centers herein propose to perform three epidemiologic studies. Study 1: A population-based, historical, prospective cohort of 10,000 kidney donors and 330 lung donors along with a comparison group of 20,660 subjects enrolled in the Health Professionals Follow-up Study and the Nurses Health Study (HPFS/NHS) will be utilized to evaluate: (a) the risk of death in both kidney and lung donors and (b) the risk of end stage renal disease (ESRD) in kidney donors. Study 2: A cross-sectional clinical study will be performed in a sample of 700 kidney donors, 330 lung donors and 1,030 yoke, sibling and spousal controls to: (a) evaluate the risk of pulmonary dysfunction in lung donors;(b) determine whether live organ donation significantly increases the risk of total comorbid burden, impaired health-related quality of life (HQRoL), mental health disturbance or psychological dysfunction;and (c) determine the cumulative risk of CKD, cardiovascular disease (CVD), hypertension and diabetes mellitus in kidney donors. Study 3: A 12-month prospective study will be performed in 400 subjects scheduled for live donor nephrectomy, to assess multiple aspects of the informed consent process. Poisson regression and competing risk model will be,used to analyze death rates and the incidence of ESRD, respectively. Multivariate regression methods will be used to assess the risks of pulmonary dysfunction, CVD, CKD, diminished HRQoL, psychological impairment and elevated comorbid indices. The proposed studies are powered at 85-93% to identify characteristics associated with prohibitive risks of adverse donor outcomes and to delineate the long-term psychosocial effects of live organ donation.