Abstract <p>This study investigates the role of nanoparticle aggregation in the axisymmetric flow and heat transfer of an electrically conducting second-grade nanofluid over a radially stretching sheet. The analysis incorporates a generalized slip condition as proposed by Thompson and Troian, along with temperature slip effects. While the framework is broadly applicable, it specifically examines the behavior of blood flow enhanced with gold nanoparticles, incorporating magnetic effects due to the blood’s electrically conducting nature. Using boundary layer approximations and suitable similarity transformations, the problem is reduced to a system of coupled ordinary differential equations (ODEs), solved numerically with MATLAB’s “bvp4c” function. Results are presented for cases with and without nanoparticle aggregation, highlighting the variations in velocity, temperature, skin friction coefficient, and Nusselt number as a function of key parameters. The findings reveal that viscoelasticity significantly modulates the effects of nanoparticle aggregation, reducing velocity near the surface while enhancing it in the outer boundary layer. Nanoparticle aggregation is observed to improve heat transfer rate by up to 9%. This research has practical implications for modeling real-world fluid flow phenomena, including blood dynamics, exotic lubricants, polymeric suspensions, and nanofluids in microchannels and capillaries, offering insights into applications ranging from biomedical engineering to advanced material processing.</p> Graphical abstract <p></p>