Lutgarde Thijs spends much of his time researching Internal medicine, Blood pressure, Cardiology, Surgery and Ambulatory. The study incorporates disciplines such as Placebo and Endocrinology in addition to Internal medicine. The Blood pressure study combines topics in areas such as Stroke and Hazard ratio.

His Cardiology study combines topics from a wide range of disciplines, such as Meta-analysis, Antihypertensive drug, Arterial stiffness and Heart rate. His Surgery research incorporates themes from Pulse pressure, Predictive value of tests and Risk factor. He works mostly in the field of Ambulatory, limiting it down to concerns involving Circadian rhythm and, occasionally, Nocturnal, Circulatory system, Correlation coefficient and Balance.