The earliest and least distinctive symptoms of rickets are restlessness and slight feverishness at night; the child sweats profusely, and continually throws off its bed-clothes. Next is noticed an unwillingness on the part of the child to be touched or moved; it seems sore all over, and has no longer any pleasure in being tossed about and caressed. The first positive evidence of rickets is given, however, by enlargement of the bones of the wrist and subsequently of the ankle, knee, and elbow joints. Then the long bones become bent and bowed, the ribs fall in laterally, their ends form knob-like projections, and the sternum projects in front, causing the well-known pigeon breast; the bones of the head are thickened, and the fontanelles remain open long after the time they are closed in healthy children; the head becomes large, flat on the top, with projecting forehead; the teeth are late in appearing. While these deformities in the bony skeleton are taking place, the general condition grows worse, fever increases, perspirations are more profuse, and the tenderness of the body becomes so great that the child dreads being touched. Appetite fails, weakness increases, the child emaciates, and has a wan, anxious, pallid look. The abdomen protrudes, and the liver and spleen are often found to be hypertrophied. When rickets prove fatal, death is caused either by lung trouble induced by the falling in of the thoracic walls, or by impaired digestion and consequent weakness, or by croup or convulsions.

Rickets may exist in a much less marked degree; the ends of the long bones may be thickened, but the constitutional symptoms may not be so marked. Recovery is the rule; and persons who have suffered from rickets in their youth may become very strong, but they are usually short, and the deformities of the bones, the bow legs, the curved spine, and the narrow chest generally remain, and often cause much misery and discomfort in after life.

If the bones be examined in rickets, it is found that in the cartilaginous extremities, where growth is most active, there is considerable enlargement, softening, and rarefaction, and that the earthy matter present is much less than in the bones of healthy children. It was hence formerly argued from this fact that rickets was caused by the want of lime salts, and that to give a child lime water and phosphate of lime would cure the rickets. This is, however, quite insufficient; moreover, many of the farinaceous foods on which rickety children are fed are rich in lime and phosphoric acid. Inasmuch as the disease of rickets is caused by food deficient in fat and albumen, so the cure of rickets lies in restoring these elements to the diet of the child.