Micro(nano)plastic (MNP) contamination has become an urgent global environmental issue, causing immeasurable potential harm to humans. However, direct evidence on the impact of MNPs on human health remains limited. This article summarizes related research hotspots, maps MNPs in various human organ systems, and emphasizes their alarming links with diseases. There is growing evidence that MNPs are present in the respiratory/digestive tract, skin surfaces, blood (vessels), and reproductive organs. The existence of these MNPs is positively correlated with the occurrence of tissue lesions, such as inflammatory bowel disease, atherosclerosis, thrombosis, and cervical cancer. MNPs can be internalized by human cells, causing oxidative stress and proinflammatory responses, and leading to genotoxicity and apoptosis. MNPs may even cross the human gutbrain axis and blood-brain barrier, inducing neurodegenerative diseases. The potential hazards of MNPs to humans require urgent attention, and additional monitoring experiments and epidemiological studies are needed to further elucidate the relevant mechanisms.