Menstruation is often irregular for the
first few years, and for several years
A measurement of the intel-
lectual development of a person, with
regard to the normal age at which that
level of achievement is attained. For
example, a 13 year-old child with
may have a mental age of 5.
development, also known as general
Mental Health Act
The Mental Health
Act (1983) details the rights of patients
and the grounds for
detaining mentally ill people against
their will. It also outlines forms of legal
guardianship for such patients.
When a person is endangering his or
her own or other people's health or
safety (for example, threatening harm
or suicide) because of a recognized
mental illness, he or she may be com-
pulsorily taken into hospital to be given
treatment. If a person breaks the law
because of a mental disorder, the courts
may remand him or her to hospital.
A hospital, formerly
known as an asylum, specializing in the
treatment of psychiatric illness.
Most admissions to mental hospitals
are for acute psychiatric illness. The
majority of admissions are voluntary,
but in some cases detention under the
Mental Health Act
may be necessary.
A general term that des-
cribes any form of psychiatric disorder.
An alcohol prepared from mint
oils. Menthol is an ingredient of several
over-the-counter inhalation preparations
used to treat a blocked or stuffy nose.
in the treatment of
also acts as a muscle relaxant.
A weak opioid
used for the short-term relief of
moderate to severe pain, such as after
surgery and during childbirth. Possible
adverse effects include nausea, vomit-
ing, and dizziness.
used to treat certain types of
Adverse effects include nausea, mouth
ulcers, and appetite loss. Rarely, it may
cause liver damage,
, and ab-
The only metal that is liquid at
room temperature. Mercury is used in
fillings for teeth (see
Toxic effects of
mercury on the body. The most com-
mon cause of mercury poisoning is
breathing in vapour given off by liquid
mercury, usually as a result of industrial
exposure. Swallowing a small amount
of liquid mercury is unlikely to lead to
Mercury compounds may
cause poisoning by absorption through
the intestines (causing nausea, vomit-
ing, diarrhoea, and abdominal pain) or
the skin (causing severe inflammation).
After entering the body, mercury accu-
mulates in organs, principally the brain
and kidneys. Mercury deposits in the
brain cause tiredness, incoordination,
excitability, tremors, and numbness in
the limbs. In severe cases, there may
be impaired vision and
posits of mercury in the kidneys may
Treatment may involve
which help the body to excrete the mer-
cury quickly; haemodialysis (see
and induced vomiting or pumping out
the stomach, if mercury has been swal-
lowed within the previous few hours.
A drug used to treat
Adverse effects of mesalazine
include nausea, diarrhoea, abdominal
pain, and headache.
ed from the Mexican peyote cactus.
abdominal disorder, mainly affecting
children, in which
become inflamed. The main
symptoms of pain and tenderness in
the abdomen may mimic appendicitis.
There may also be mild fever. Mesen-
teric lymphadenitis usually clears up
rapidly, needing only
reduce pain and fever.
A membrane that attaches
organs to the abdominal wall. The term
is used particularly to refer to the mem-
branous fold that encloses the small
intestine, attaching it to the back of the