irritants or blockages. A cough is pro-
ductive when it brings up mucus or
sputum and unproductive, or dry, when it
does not. Many coughs are due to irrita-
tion of the airways by dust, smoke (see
cough, smoker’s), or a viral infection of
the upper respiratory tract (see cold,
common; laryngitis; pharyngitis; trache-
itis). Coughing is a feature of bronchitis,
asthma, pneumonia, and lung cancer.
Over-the-counter cough remediesare
available; but, in general, they just ease
symptoms. More specific treatment is
directed at the underlying disorder.
coughing up bloodA symptom, medi-
cally known as haemoptysis, that is
caused by rupture of a blood vessel in
the air-ways, lungs, nose, or throat. The
coughed-up blood may appear as bright-
red or rusty-brown streaks, clots in the
sputum, a pinkish froth, or, more rarely,
blood alone. In all cases, medical assess-
ment is needed. Many disorders can
cause haemoptysis. The most common
are infections, such as pneumoniaor
bronchitis; and congestionin and rup-
ture of blood vessels in the lungs due to
heart failure, mitral stenosis, or pulmon-
ary embolism. A cancerous tumour can
also produce haemoptysis by eroding
the wall of a blood vessel.
Investigations into coughing up blood
include chest X-ray, and, in some cases,
bronchoscopy. In about a 3rd of cases, no
underlying cause is found. Treatment
depends on the cause.
cough remediesOver-the-counter med-
icationsfor treating a cough. There are
various preparations, but the effective-
ness of most is unproven. Expectorant
cough remedies are purported to en-
courage expulsion of sputum. Cough
suppressants, which control the cough-
ing reflex, include some antihistamine
drugsand codeine. All cough suppres-
sants may cause drowsiness.
cough, smoker’sA recurrent coughin
smokers. The cough is usually triggered
by the accumulation of thick sputum in
the airways due to inflammation caused
by smoking. Giving up smoking usually
stops the cough but it may take time. In
general, the longer a person has been
smoking, the longer it will take. Smok-
ers with a cough should seek medical
advice, particularly if their cough
changes, because smoking is associated
with lung cancer(see tobacco-smoking).
counsellingAdvice and psychological
support from health professionals to
help people deal with personal difficul-
ties. Counselling is used to address
problems at school, work, or in the fam-
ily; provide advice on medical problems
and sexual and marital problems; help
people to deal with addictions; and pro-
vide support during life crises. Types of
counselling include genetic counselling,
trauma counselling, and sex therapy.
In most cases counselling is a one-to-
one activity, but it may also be carried
out in small groups. (See also child
guidance; family therapy; marriage guid-
ance; psychotherapy.)
cowpoxAn infection caused by the vac-
cinia virus, which usually affects cows.
This virus was used in the past to confer
immunity against smallpox.
COX-2 inhibitor drugsA group of
non-steroidal anti-inflammatory drugs
(NSAIDs) that cause less stomach irrita-
tion as a side effect than other NSAIDs.
Examples of COX-2 inhibitors include
celecoxiband rofecoxib.
coxa varaA deformity of the hipin
which the angle between the neck and
head of the femur(thigh-bone) and the
shaft of the femur is reduced, resulting
in shortening of the leg, pain and stiff-
ness in the hip, and a limp. The most
common cause is a fracture to the neck
of the femur or, during adolescence,
injury to the developing part of the head
of the bone. Coxa vara can also occur if
the bone tissue in the neck of the femur
is soft, a condition that may be congen-
italor the result of a bone disorder such
as ricketsor Paget’s disease. Treatment
may include surgery (see osteotomy).
coxsackievirusOne of a group of
virusesresponsible for a broad range of
diseases. There are 2 main types of cox-
sackievirus: A and B. The best known of
the type A infections is hand, foot, and
mouth disease, a common childhood
disorder characterized by blistering of the
mouth, hands, and feet. Type B viruses
can cause serious illnesses such as
meningitis, pericarditis, and pneumonia.
crab liceSee pubic lice.COUGHING UP BLOOD CRAB LICE
C