An elevation in bone density in one or more diaphyses. Sclerosis is normally detected on a radiograph as an area of increased opacity. The phenotype is Diaphyseal sclerosis (HP_0003034, a Human Phenotype Ontology id). Also known as: Craniodiaphyseal osteosclerosis, Diaphyseal osteosclerosis, Increased bone density in shaft of long bone.