Webster's New World Medical Dictionary

H. flu
Haemophilus influenzae type B.
H. flu immunization
Haemophilus influenzae
type B immunization.
H. heilmannii
Helicobacter heilmannii.
H. pylori
Helicobacter pylori.
Haemophilus influenzae type B
A bacterium
that is capable of causing a range of diseases,
including ear infections, soft tissue infection (cel-
lulitis), arthritis, upper respiratory infections, and
pneumonia; as well as such serious, invasive infec-
tions as meningitis with potential brain damage and
epiglottitis with airway obstruction. Abbreviated
HIB. HIB spreads by droplet through coughs and
sneezing. About half the cases of HIB present as
meningitis with fever, headache, and stiff neck. The
remainder present as cellulitis, arthritis, or sepsis
(bloodstream infection). About 5 percent of cases
are fatal. Up to 20 percent of survivors of HIB have
permanent hearing loss. More than 90 percent of all
HIB infections occur in children 5 years or
younger—the peak attack rate is at 6 to 12 months
of age. See also 
Haemophilus influenzae type B
immunization.
Haemophilus influenzae type B immunization
An immunization designed to prevent diseases
caused by Haemophilus influenzae type B (HIB). In
the US, the HIB vaccine is usually given at 2, 4, and
6 months of age, with a final booster at 12 to 15
months of age. The HIB vaccine rarely causes severe
reactions, and it has almost eradicated HIB-related
diseases in children. 
hair, exclamation point
See 
exclamation
point hair.
hair, lanugal
See 
lanugo.
hair follicle
See 
follicle.
hairball
A wad of swallowed hair. Hairballs
sometimes cause blockage of the digestive system,
especially at the exit of the stomach. Also called
trichobezoar.