Transient neurological events in young adults present a diagnostic challenge in primary care, particularly when vascular risk factors are absent. Although sometimes attributed to benign causes, brief recurrent focal deficits may represent transient ischaemic attacks (TIA). Primary care is essential for early recognition, timely referral, and follow-up.A healthy man in his late twenties consulted after three short episodes of left-sided weakness and speech disturbance occurring within one day. Each lasted under ten minutes and resolved completely. He denied headache, fever, trauma, or substance use. On examination he was asymptomatic and neurologically intact. Vital signs and cardiovascular findings were normal. Initial blood tests and multimodal CT showed no abnormalities. Continuous cardiac monitoring detected no arrhythmias, and conventional echocardiography was unremarkable. Given the recurrent, focal nature of the symptoms, a bubble-contrast transcranial Doppler was requested, revealing a right-to-left shunt. Outpatient evaluation included brain MRI (normal) and transoesophageal echocardiogram confirming a patent foramen ovale (PFO) with microbubble passage into the left chambers. He was started on antiplatelet therapy and referred to cardiology for further management.The case illustrates a frequent but often under-recognised cause of transient deficits in young adults. Its originality lies not in rarity, but in demonstrating how apparently isolated episodes with normal initial testing can conceal a relevant cardiac source of embolism. The narrative emphasises clinical reasoning in primary care rather than highly specific details, making the case widely applicable.Stereotyped focal neurological episodes in young patients should prompt structured assessment for possible TIA. Early consideration of intracardiac shunts can prevent diagnostic delay. Strengthening access to Doppler screening and clear referral pathways may improve care. The case highlights the importance of continuity and longitudinal assessment in primary care.Although migraine aura, focal seizures, metabolic disturbances, and functional symptoms may mimic TIA, clustering of brief unilateral deficits strongly supports a vascular mechanism. When routine studies are normal, PFO should be considered as a potential route for paradoxical embolism.Primary care has a central role in recognising transient neurological symptoms in young adults. Early identification of PFO as a possible cause enables timely prevention strategies and may reduce long-term cerebrovascular risk.