by Anne Marie Helmenstine, Ph.D. Updated June 13, 2014. Definition: A molecular orbital is an orbital or wavefunction of a molecule's electron. Electrons around a molecule can be associated with more than one atom and are often expressed as a combination of atomic orbitals.
Hereditary angioedema is a disorder characterized by recurrent episodes of severe swelling (angioedema). The most common areas of the body to develop swelling are the limbs, face, intestinal tract, and airway. Minor trauma or stress may trigger an attack, but swelling often occurs without a known trigger.
Angioedema is a skin reaction similar to hives or urticaria. It is most often characterised by an abrupt and short-lived swelling of the skin and mucous membranes. All parts of the body may be affected but swelling most often occurs around the eyes and lips.