Lifestyle, illness and treatment factors in people with bipolar disorder (BD) may confer additional risk of morbidity and mortality to the increasing rates of obesity, metabolic syndrome, diabetes mellitus and cardiovascular mortality in the general population.The aim of this review is to examine whether the risk of obesity and related morbidity and mortality are raised in BD, and possible contributory effects of lifestyle, illness and treatment factors to this risk.Systematic search of Medline and Cochrane Collaboration for relevant studies followed by a critical review of literature was carried out.Mortality from cardiovascular causes and pulmonary embolism (standardized mortality ratio approximately 2.0), and morbidity from obesity and type 2 diabetes mellitus may be increased in BD compared to the general population. Reduced exercise and poor diet, frequent depressive episodes, comorbidity with substance misuse and poor quality general medical care contribute to the additional risk of these medical problems in people with BD. There is no evidence that patients with BD are more sensitive than other patients to weight gain and medical problems associated with long-term use of psychotropic medication; in fact long-term treatment with lithium, antipsychotics and tricyclic antidepressants may reduce overall mortality. Psychiatrists, general practitioners and other health professionals should work together to systematically assess and manage weight gain and related medical problems to reduce the morbidity and mortality associated with obesity in BD. There is insufficient evidence to associate any of these factors with specific drug treatments. More research is required to understand how BD changes the risk for physical health comorbidity.