Petechiae are tiny pinpoint spots of bleeding under the skin or mucous membranes, caused by capillaries leaking small amounts of blood. In nutrition, they are a recognised sign of scurvy: vitamin C is essential for collagen synthesis in blood vessel walls, and deficiency makes capillaries fragile, producing petechiae around hair follicles alongside bleeding gums and poor wound healing. They can also indicate thrombocytopenia, infections, or trauma, so clinicians interpret them in context rather than assuming diet. The appearance of petechiae in a malnourished patient prompts assessment of vitamin C status along with other micronutrients, and the spots resolve as nutrition is restored. As a clinical sign, they illustrate how visibly the body’s structural proteins depend on steady micronutrient supply.