Webster's New World Medical Dictionary

sickle cell anemia
See 
anemia, sickle cell.
sickle cell disease
See 
anemia, sickle cell.
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 their chil-
dren has a 25 percent chance of having sickle cell
disease.
sickle hemoglobin
See 
hemoglobin S.
sickness, altitude
See 
altitude sickness.
sickness, motion
See 
motion sickness.
sickness, mountain
See 
altitude sickness.
side effect 1
Problems that occur when treatment
goes beyond the desired effect. An example is hem-
orrhage 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 counts, hair loss, and mouth
sores.
SIDS
Sudden infant death syndrome.
sig
Signature.
sight, day
See 
nyctanopia.
sigmoid
In human anatomy, the lower colon (the
lower portion of the large bowel). Sigmoid is short
for sigmoid colon. From the Greek letter sigma,
which is shaped like a C. Sigmoid also means
curved in two directions like the letter S. For exam-
ple, a sigmoid curve is an S-shaped curve.
sigmoidoscope
A lighted instrument that is used
to view the inside of the lower colon.
sigmoidoscopy
A procedure in which a physician
inserts a viewing tube (sigmoidoscope) into the rec-
tum for the purpose of inspecting the lower colon
and rectum. If an abnormal area is detected, a
biopsy can be performed.
sign
Any objective evidence of disease, as
opposed to a symptom, which is, by nature, subjec-
tive. For example, gross blood in the stool is a sign
of disease; it is evidence that can be recognized by
the patient, physician, nurse, or someone else.
Abdominal pain is a symptom; it is something only
the patient can perceive.
signature 1
The part of the prescription that con-
tains the physician’s directions to the patient. For
example, the signature might say “take twice daily
with food.” Also known as sig.