A 30-year-old male with no relevant medical history presented with a 24-hour onset of dyspnea. He reported recent alcohol and cocaine use over the weekend. He denied fever or previous trauma.To determine the etiology of sudden dyspnea in a young patient without classic risk factors, emphasizing the relevance of substance use history in the diagnostic process.The evaluation began in Primary Care (93% oxygen saturation, pathological lung sounds). A point-of-care lung ultrasound revealed an image compatible with a pulmonary infarction. To confirm the findings, the patient was referred to the hospital for D-dimer testing and a CT pulmonary angiogram (CTPA).The CTPA confirmed a bilateral pulmonary embolism (PE), and laboratory tests showed elevated D-dimer levels. After ruling out differential diagnoses such as pneumonia, pneumothorax, or myocarditis, the thrombotic origin was confirmed.Cocaine exerts a direct vasoconstrictive effect on the pulmonary endothelium, facilitating thrombus formation even in the absence of comorbidities. In young patients, isolated dyspnea following substance use should raise suspicion of vascular events, as cocaine acts as a potent thrombotic trigger.This case highlights the critical role of Primary Care in the early detection of life-threatening conditions. Cocaine use is an independent risk factor for PE. The patient was stabilized with anticoagulant therapy and outpatient follow-up.