YAG (neodymium-doped yttrium aluminium garnet) is a crystal that is used as a laser medium for solid-state lasers. The triply ionized neodymium[ Nd(III)] dopant (i.e. a substance added in minute amounts to another pure material to change its conductivity) usually substitutes a small fraction of the yttrium ions in the structure of the host crystal, since the two ions are of similar size.

Nd: YAG laser beams can be used to treat the following skin disorders.

• Spider and thread veins in the face (cheek, temporal region, nasal dorsum, forehead) and legs.
  Vascular birthmark (capillary vascular malformation)
• Varicose veins
• Facial veins (telangiectasia)
• Haemangioma(a vascular tumour)