Dictionary

SIDS Sudden infant death syndrome.

side effect 1 Problems that occur when treatment goes beyond the desired effect. An example is hemorrhage due to the use of too much anticoagulant (blood thinning medication). 2 Problems that occur in addition to the desired therapeutic effect. For example, the common side effects of cancer treatment include fatigue, nausea, vomiting, decreased blood cell…

sickness, mountain See altitude sickness.

sickle hemoglobin See hemoglobin S.

sickle cell trait The condition in which a person has only one copy of the gene for sickle cell (and is called a sickle heterozygote) but does not have sickle cell disease (which requires two copies of the sickle cell gene). If two people with sickle cell trait mate and have children together, each of…

sickle cell disease See anemia, sickle cell.

sickle cell anemia See anemia, sickle cell.

sick sinus syndrome A condition that features symptoms including dizziness, confusion, fainting, and heart failure that is due to a problem with the sinoatrial node (SA node) of the heart, which acts as the body’s natural pacemaker. If the SA node is not functioning normally, the patient usually has an abnormally slow heart rate (bradycardia),…

sicca syndrome See Sjögren syndrome.

sibship The relationship between the children born to a set of parents.

sibling A brother or sister.

Siamese twins Identical (monozygotic) twins that do not separate fully from one another but remain partially united due to the incomplete division of one fertilized ovum. Such twins are known medically as conjoined twins. Conjoined twins are popularly known as Siamese twins after Chang and Eng, the celebrated conjoined Chinese twins born in Siam (Thailand)…