Scurvy, or hypovitaminosis C, is "an acquired blood vessel disorder caused by severe deficiency of vitamin C (ascorbic acid) in the diet leading to defective collagen formation in small blood vessels. Scurvy is characterized by bleeding in any tissue, weakness, anemia, spongy gums, and a brawny induration of the muscles of the calves and legs." In other words, it is the manifestation of a deficiency disease.
Scurvy was a major health problem aboard early sailing vessels for which fresh produce was not available. James Lind, although he did not know the actual deficiency, introduced the use of giving citrus juices to Royal Navy sailors. The colloquial term, "limey", for a British sailor comes from his successful treatment.