H–I

hemoptysis Bleeding from the LUNGS, which typ-
ically manifests through BLOOD in the SPUTUM.
Hemoptysis is typically frothy and bright red,
though can sometimes be difficult to distinguish
from blood that might originate in the ESOPHAGUS
or STOMACH.

Hemoptysis that produces a volume of

blood greater than the equivalent of

two or three teaspoonfuls is a medical

emergency that may represent hemor-

rhage and requires immediate treat-

ment.

Hemoptysis is a symptom of numerous health
conditions affecting the lungs, and may appear as
blood-streaked sputum or primarily blood with lit-
tle apparent sputum present. The diagnostic path
includes chest X-rays, blood tests, and sputum cul-
tures. Lung hemorrhage is a surgical emergency
that generally requires immediate intervention to
locate and stop the source of bleeding, commonly
a perforated ARTERY. Treatment for less severe
bleeding focuses on the underlying cause. The
most common cause overall of hemoptysis is
BRONCHITIS.

COMMON CAUSES OF HEMOPTYSIS

BRONCHIECTASIS BRONCHITIS
CYSTIC FIBROSIS LUNG CANCER
PNEUMONIA PULMONARY EMBOLISM
TUBERCULOSIS violent coughing
Wegener’s granulomatosis

See also ANEMIA; GASTROINTESTINAL BLEEDING.

hiccups Dysfunctional or out-of-sequence con-
tractions (spasms) of the DIAPHRAGM. Hiccups gen-

erally occur rhythmically in episodes that typically

contain four to several dozen contractions. An

individual tends to have a personally consistent

pattern. Though doctors know the mechanics of

hiccups, no one knows what causes hiccups or

what, if any, purpose they serve. For most people

hiccups are nothing more than an annoyance.

However, prolonged attacks can have health con-

sequences.

There is no certain cure for hiccups, though

recommended remedies are abundant. Some

remedies, such as swallowing a spoonful of sugar

or sniffing an ammonia capsule, irritate the air-

ways. Swallowing ice water may activate nerves in

the ESOPHAGUS that diffuse the NERVE impulses

causing the diaphragm to contract. BREATHINGinto

a paper bag raises the percentage of carbon diox-

ide in the BLOOD, which alters the brain signals to

the diaphragm. It is important that any prospec-

tive cure carry little risk of causing harm.

Doctors may treat persistent hiccups with med-

ications that are mildly sedating, such as anti-

seizure or anticholinergic medications. A mild

anesthetic may slow the signals from the brain-

stem. Mild MUSCLErelaxants and tricyclic antide-

pressants are also successful in some people.

Extended hiccups may result in vasovagal nerve

irritation that causes ARRHYTHMIA(irregularities in

the heartbeat). In most circumstances of pro-

longed hiccups, treating underlying health condi-

tions stops the hiccups.

See also HYPERVENTILATION; MYOCLONUS; SPASM.

hyperventilation Rapid, shallow BREATHING that

causes carbon dioxide levels in the BLOODto drop

below normal. As the balance between carbon

dioxide and other gases in the blood is essential

for normal pulmonary and cardiovascular func-

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